mariadb/storage/xtradb/row/row0sel.cc

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/*****************************************************************************
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Copyright (c) 1997, 2016, Oracle and/or its affiliates. All Rights Reserved.
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Copyright (c) 2008, Google Inc.
Copyright (c) 2015, MariaDB Corporation.
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Portions of this file contain modifications contributed and copyrighted by
Google, Inc. Those modifications are gratefully acknowledged and are described
briefly in the InnoDB documentation. The contributions by Google are
incorporated with their permission, and subject to the conditions contained in
the file COPYING.Google.
This program is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free Software
Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with
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this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Suite 500, Boston, MA 02110-1335 USA
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*****************************************************************************/
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/***************************************************//**
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@file row/row0sel.cc
Select
Created 12/19/1997 Heikki Tuuri
*******************************************************/
#include "row0sel.h"
#ifdef UNIV_NONINL
#include "row0sel.ic"
#endif
#include "dict0dict.h"
#include "dict0boot.h"
#include "trx0undo.h"
#include "trx0trx.h"
#include "btr0btr.h"
#include "btr0cur.h"
#include "btr0sea.h"
#include "mach0data.h"
#include "que0que.h"
#include "row0upd.h"
#include "row0row.h"
#include "row0vers.h"
#include "rem0cmp.h"
#include "lock0lock.h"
#include "eval0eval.h"
#include "pars0sym.h"
#include "pars0pars.h"
#include "row0mysql.h"
#include "read0read.h"
#include "buf0lru.h"
#include "srv0srv.h"
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#include "ha_prototypes.h"
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#include "srv0start.h"
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#include "m_string.h" /* for my_sys.h */
#include "my_sys.h" /* DEBUG_SYNC_C */
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#include "my_compare.h" /* enum icp_result */
/* Maximum number of rows to prefetch; MySQL interface has another parameter */
#define SEL_MAX_N_PREFETCH 16
/* Number of rows fetched, after which to start prefetching; MySQL interface
has another parameter */
#define SEL_PREFETCH_LIMIT 1
/* When a select has accessed about this many pages, it returns control back
to que_run_threads: this is to allow canceling runaway queries */
#define SEL_COST_LIMIT 100
/* Flags for search shortcut */
#define SEL_FOUND 0
#define SEL_EXHAUSTED 1
#define SEL_RETRY 2
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/********************************************************************//**
Returns TRUE if the user-defined column in a secondary index record
is alphabetically the same as the corresponding BLOB column in the clustered
index record.
NOTE: the comparison is NOT done as a binary comparison, but character
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fields are compared with collation!
@return TRUE if the columns are equal */
static
ibool
row_sel_sec_rec_is_for_blob(
/*========================*/
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ulint mtype, /*!< in: main type */
ulint prtype, /*!< in: precise type */
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ulint mbminmaxlen, /*!< in: minimum and maximum length of
a multi-byte character */
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const byte* clust_field, /*!< in: the locally stored part of
the clustered index column, including
the BLOB pointer; the clustered
index record must be covered by
a lock or a page latch to protect it
against deletion (rollback or purge) */
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ulint clust_len, /*!< in: length of clust_field */
const byte* sec_field, /*!< in: column in secondary index */
ulint sec_len, /*!< in: length of sec_field */
ulint prefix_len, /*!< in: index column prefix length
in bytes */
dict_table_t* table) /*!< in: table */
{
ulint len;
byte buf[REC_VERSION_56_MAX_INDEX_COL_LEN];
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ulint zip_size = dict_tf_get_zip_size(table->flags);
/* This function should never be invoked on an Antelope format
table, because they should always contain enough prefix in the
clustered index record. */
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ut_ad(dict_table_get_format(table) >= UNIV_FORMAT_B);
ut_a(clust_len >= BTR_EXTERN_FIELD_REF_SIZE);
ut_ad(prefix_len >= sec_len);
ut_ad(prefix_len > 0);
ut_a(prefix_len <= sizeof buf);
if (UNIV_UNLIKELY
(!memcmp(clust_field + clust_len - BTR_EXTERN_FIELD_REF_SIZE,
field_ref_zero, BTR_EXTERN_FIELD_REF_SIZE))) {
/* The externally stored field was not written yet.
This record should only be seen by
recv_recovery_rollback_active() or any
TRX_ISO_READ_UNCOMMITTED transactions. */
return(FALSE);
}
len = btr_copy_externally_stored_field_prefix(buf, prefix_len,
zip_size,
clust_field, clust_len,
NULL);
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if (UNIV_UNLIKELY(len == 0)) {
/* The BLOB was being deleted as the server crashed.
There should not be any secondary index records
referring to this clustered index record, because
btr_free_externally_stored_field() is called after all
secondary index entries of the row have been purged. */
return(FALSE);
}
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len = dtype_get_at_most_n_mbchars(prtype, mbminmaxlen,
prefix_len, len, (const char*) buf);
return(!cmp_data_data(mtype, prtype, buf, len, sec_field, sec_len));
}
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/********************************************************************//**
Returns TRUE if the user-defined column values in a secondary index record
are alphabetically the same as the corresponding columns in the clustered
index record.
NOTE: the comparison is NOT done as a binary comparison, but character
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fields are compared with collation!
@return TRUE if the secondary record is equal to the corresponding
fields in the clustered record, when compared with collation;
FALSE if not equal or if the clustered record has been marked for deletion */
static
ibool
row_sel_sec_rec_is_for_clust_rec(
/*=============================*/
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const rec_t* sec_rec, /*!< in: secondary index record */
dict_index_t* sec_index, /*!< in: secondary index */
const rec_t* clust_rec, /*!< in: clustered index record;
must be protected by a lock or
a page latch against deletion
in rollback or purge */
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dict_index_t* clust_index) /*!< in: clustered index */
{
const byte* sec_field;
ulint sec_len;
const byte* clust_field;
ulint n;
ulint i;
mem_heap_t* heap = NULL;
ulint clust_offsets_[REC_OFFS_NORMAL_SIZE];
ulint sec_offsets_[REC_OFFS_SMALL_SIZE];
ulint* clust_offs = clust_offsets_;
ulint* sec_offs = sec_offsets_;
ibool is_equal = TRUE;
rec_offs_init(clust_offsets_);
rec_offs_init(sec_offsets_);
if (rec_get_deleted_flag(clust_rec,
dict_table_is_comp(clust_index->table))) {
/* The clustered index record is delete-marked;
it is not visible in the read view. Besides,
if there are any externally stored columns,
some of them may have already been purged. */
return(FALSE);
}
clust_offs = rec_get_offsets(clust_rec, clust_index, clust_offs,
ULINT_UNDEFINED, &heap);
sec_offs = rec_get_offsets(sec_rec, sec_index, sec_offs,
ULINT_UNDEFINED, &heap);
n = dict_index_get_n_ordering_defined_by_user(sec_index);
for (i = 0; i < n; i++) {
const dict_field_t* ifield;
const dict_col_t* col;
ulint clust_pos;
ulint clust_len;
ulint len;
ifield = dict_index_get_nth_field(sec_index, i);
col = dict_field_get_col(ifield);
clust_pos = dict_col_get_clust_pos(col, clust_index);
clust_field = rec_get_nth_field(
clust_rec, clust_offs, clust_pos, &clust_len);
sec_field = rec_get_nth_field(sec_rec, sec_offs, i, &sec_len);
len = clust_len;
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if (ifield->prefix_len > 0 && len != UNIV_SQL_NULL
&& sec_len != UNIV_SQL_NULL) {
if (rec_offs_nth_extern(clust_offs, clust_pos)) {
len -= BTR_EXTERN_FIELD_REF_SIZE;
}
len = dtype_get_at_most_n_mbchars(
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col->prtype, col->mbminmaxlen,
ifield->prefix_len, len, (char*) clust_field);
if (rec_offs_nth_extern(clust_offs, clust_pos)
&& len < sec_len) {
if (!row_sel_sec_rec_is_for_blob(
col->mtype, col->prtype,
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col->mbminmaxlen,
clust_field, clust_len,
sec_field, sec_len,
ifield->prefix_len,
clust_index->table)) {
goto inequal;
}
continue;
}
}
if (0 != cmp_data_data(col->mtype, col->prtype,
clust_field, len,
sec_field, sec_len)) {
inequal:
is_equal = FALSE;
goto func_exit;
}
}
func_exit:
if (UNIV_LIKELY_NULL(heap)) {
mem_heap_free(heap);
}
return(is_equal);
}
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/*********************************************************************//**
Creates a select node struct.
@return own: select node struct */
UNIV_INTERN
sel_node_t*
sel_node_create(
/*============*/
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mem_heap_t* heap) /*!< in: memory heap where created */
{
sel_node_t* node;
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node = static_cast<sel_node_t*>(
mem_heap_alloc(heap, sizeof(sel_node_t)));
node->common.type = QUE_NODE_SELECT;
node->state = SEL_NODE_OPEN;
node->plans = NULL;
return(node);
}
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/*********************************************************************//**
Frees the memory private to a select node when a query graph is freed,
does not free the heap where the node was originally created. */
UNIV_INTERN
void
sel_node_free_private(
/*==================*/
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sel_node_t* node) /*!< in: select node struct */
{
ulint i;
plan_t* plan;
if (node->plans != NULL) {
for (i = 0; i < node->n_tables; i++) {
plan = sel_node_get_nth_plan(node, i);
btr_pcur_close(&(plan->pcur));
btr_pcur_close(&(plan->clust_pcur));
if (plan->old_vers_heap) {
mem_heap_free(plan->old_vers_heap);
}
}
}
}
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/*********************************************************************//**
Evaluates the values in a select list. If there are aggregate functions,
their argument value is added to the aggregate total. */
UNIV_INLINE
void
sel_eval_select_list(
/*=================*/
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sel_node_t* node) /*!< in: select node */
{
que_node_t* exp;
exp = node->select_list;
while (exp) {
eval_exp(exp);
exp = que_node_get_next(exp);
}
}
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/*********************************************************************//**
Assigns the values in the select list to the possible into-variables in
SELECT ... INTO ... */
UNIV_INLINE
void
sel_assign_into_var_values(
/*=======================*/
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sym_node_t* var, /*!< in: first variable in a list of
variables */
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sel_node_t* node) /*!< in: select node */
{
que_node_t* exp;
if (var == NULL) {
return;
}
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for (exp = node->select_list;
var != 0;
var = static_cast<sym_node_t*>(que_node_get_next(var))) {
ut_ad(exp);
eval_node_copy_val(var->alias, exp);
exp = que_node_get_next(exp);
}
}
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/*********************************************************************//**
Resets the aggregate value totals in the select list of an aggregate type
query. */
UNIV_INLINE
void
sel_reset_aggregate_vals(
/*=====================*/
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sel_node_t* node) /*!< in: select node */
{
func_node_t* func_node;
ut_ad(node->is_aggregate);
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for (func_node = static_cast<func_node_t*>(node->select_list);
func_node != 0;
func_node = static_cast<func_node_t*>(
que_node_get_next(func_node))) {
eval_node_set_int_val(func_node, 0);
}
node->aggregate_already_fetched = FALSE;
}
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/*********************************************************************//**
Copies the input variable values when an explicit cursor is opened. */
UNIV_INLINE
void
row_sel_copy_input_variable_vals(
/*=============================*/
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sel_node_t* node) /*!< in: select node */
{
sym_node_t* var;
var = UT_LIST_GET_FIRST(node->copy_variables);
while (var) {
eval_node_copy_val(var, var->alias);
var->indirection = NULL;
var = UT_LIST_GET_NEXT(col_var_list, var);
}
}
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/*********************************************************************//**
Fetches the column values from a record. */
static
void
row_sel_fetch_columns(
/*==================*/
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dict_index_t* index, /*!< in: record index */
const rec_t* rec, /*!< in: record in a clustered or non-clustered
index; must be protected by a page latch */
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const ulint* offsets,/*!< in: rec_get_offsets(rec, index) */
sym_node_t* column) /*!< in: first column in a column list, or
NULL */
{
dfield_t* val;
ulint index_type;
ulint field_no;
const byte* data;
ulint len;
ut_ad(rec_offs_validate(rec, index, offsets));
if (dict_index_is_clust(index)) {
index_type = SYM_CLUST_FIELD_NO;
} else {
index_type = SYM_SEC_FIELD_NO;
}
while (column) {
mem_heap_t* heap = NULL;
ibool needs_copy;
field_no = column->field_nos[index_type];
if (field_no != ULINT_UNDEFINED) {
if (UNIV_UNLIKELY(rec_offs_nth_extern(offsets,
field_no))) {
/* Copy an externally stored field to the
temporary heap, if possible. */
heap = mem_heap_create(1);
data = btr_rec_copy_externally_stored_field(
rec, offsets,
dict_table_zip_size(index->table),
field_no, &len, heap, NULL);
/* data == NULL means that the
externally stored field was not
written yet. This record
should only be seen by
recv_recovery_rollback_active() or any
TRX_ISO_READ_UNCOMMITTED
transactions. The InnoDB SQL parser
(the sole caller of this function)
does not implement READ UNCOMMITTED,
and it is not involved during rollback. */
ut_a(data);
ut_a(len != UNIV_SQL_NULL);
needs_copy = TRUE;
} else {
data = rec_get_nth_field(rec, offsets,
field_no, &len);
needs_copy = column->copy_val;
}
if (needs_copy) {
eval_node_copy_and_alloc_val(column, data,
len);
} else {
val = que_node_get_val(column);
dfield_set_data(val, data, len);
}
if (UNIV_LIKELY_NULL(heap)) {
mem_heap_free(heap);
}
}
column = UT_LIST_GET_NEXT(col_var_list, column);
}
}
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/*********************************************************************//**
Allocates a prefetch buffer for a column when prefetch is first time done. */
static
void
sel_col_prefetch_buf_alloc(
/*=======================*/
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sym_node_t* column) /*!< in: symbol table node for a column */
{
sel_buf_t* sel_buf;
ulint i;
ut_ad(que_node_get_type(column) == QUE_NODE_SYMBOL);
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column->prefetch_buf = static_cast<sel_buf_t*>(
mem_alloc(SEL_MAX_N_PREFETCH * sizeof(sel_buf_t)));
for (i = 0; i < SEL_MAX_N_PREFETCH; i++) {
sel_buf = column->prefetch_buf + i;
sel_buf->data = NULL;
sel_buf->len = 0;
sel_buf->val_buf_size = 0;
}
}
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/*********************************************************************//**
Frees a prefetch buffer for a column, including the dynamically allocated
memory for data stored there. */
UNIV_INTERN
void
sel_col_prefetch_buf_free(
/*======================*/
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sel_buf_t* prefetch_buf) /*!< in, own: prefetch buffer */
{
sel_buf_t* sel_buf;
ulint i;
for (i = 0; i < SEL_MAX_N_PREFETCH; i++) {
sel_buf = prefetch_buf + i;
if (sel_buf->val_buf_size > 0) {
mem_free(sel_buf->data);
}
}
mem_free(prefetch_buf);
}
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/*********************************************************************//**
Pops the column values for a prefetched, cached row from the column prefetch
buffers and places them to the val fields in the column nodes. */
static
void
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sel_dequeue_prefetched_row(
/*=======================*/
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plan_t* plan) /*!< in: plan node for a table */
{
sym_node_t* column;
sel_buf_t* sel_buf;
dfield_t* val;
byte* data;
ulint len;
ulint val_buf_size;
ut_ad(plan->n_rows_prefetched > 0);
column = UT_LIST_GET_FIRST(plan->columns);
while (column) {
val = que_node_get_val(column);
if (!column->copy_val) {
/* We did not really push any value for the
column */
ut_ad(!column->prefetch_buf);
ut_ad(que_node_get_val_buf_size(column) == 0);
ut_d(dfield_set_null(val));
goto next_col;
}
ut_ad(column->prefetch_buf);
ut_ad(!dfield_is_ext(val));
sel_buf = column->prefetch_buf + plan->first_prefetched;
data = sel_buf->data;
len = sel_buf->len;
val_buf_size = sel_buf->val_buf_size;
/* We must keep track of the allocated memory for
column values to be able to free it later: therefore
we swap the values for sel_buf and val */
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sel_buf->data = static_cast<byte*>(dfield_get_data(val));
sel_buf->len = dfield_get_len(val);
sel_buf->val_buf_size = que_node_get_val_buf_size(column);
dfield_set_data(val, data, len);
que_node_set_val_buf_size(column, val_buf_size);
next_col:
column = UT_LIST_GET_NEXT(col_var_list, column);
}
plan->n_rows_prefetched--;
plan->first_prefetched++;
}
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/*********************************************************************//**
Pushes the column values for a prefetched, cached row to the column prefetch
buffers from the val fields in the column nodes. */
UNIV_INLINE
void
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sel_enqueue_prefetched_row(
/*=======================*/
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plan_t* plan) /*!< in: plan node for a table */
{
sym_node_t* column;
sel_buf_t* sel_buf;
dfield_t* val;
byte* data;
ulint len;
ulint pos;
ulint val_buf_size;
if (plan->n_rows_prefetched == 0) {
pos = 0;
plan->first_prefetched = 0;
} else {
pos = plan->n_rows_prefetched;
/* We have the convention that pushing new rows starts only
after the prefetch stack has been emptied: */
ut_ad(plan->first_prefetched == 0);
}
plan->n_rows_prefetched++;
ut_ad(pos < SEL_MAX_N_PREFETCH);
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for (column = UT_LIST_GET_FIRST(plan->columns);
column != 0;
column = UT_LIST_GET_NEXT(col_var_list, column)) {
if (!column->copy_val) {
/* There is no sense to push pointers to database
page fields when we do not keep latch on the page! */
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continue;
}
if (!column->prefetch_buf) {
/* Allocate a new prefetch buffer */
sel_col_prefetch_buf_alloc(column);
}
sel_buf = column->prefetch_buf + pos;
val = que_node_get_val(column);
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data = static_cast<byte*>(dfield_get_data(val));
len = dfield_get_len(val);
val_buf_size = que_node_get_val_buf_size(column);
/* We must keep track of the allocated memory for
column values to be able to free it later: therefore
we swap the values for sel_buf and val */
dfield_set_data(val, sel_buf->data, sel_buf->len);
que_node_set_val_buf_size(column, sel_buf->val_buf_size);
sel_buf->data = data;
sel_buf->len = len;
sel_buf->val_buf_size = val_buf_size;
}
}
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/*********************************************************************//**
Builds a previous version of a clustered index record for a consistent read
@return DB_SUCCESS or error code */
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static MY_ATTRIBUTE((nonnull, warn_unused_result))
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dberr_t
row_sel_build_prev_vers(
/*====================*/
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read_view_t* read_view, /*!< in: read view */
dict_index_t* index, /*!< in: plan node for table */
rec_t* rec, /*!< in: record in a clustered index */
ulint** offsets, /*!< in/out: offsets returned by
rec_get_offsets(rec, plan->index) */
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mem_heap_t** offset_heap, /*!< in/out: memory heap from which
the offsets are allocated */
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mem_heap_t** old_vers_heap, /*!< out: old version heap to use */
rec_t** old_vers, /*!< out: old version, or NULL if the
record does not exist in the view:
i.e., it was freshly inserted
afterwards */
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mtr_t* mtr) /*!< in: mtr */
{
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dberr_t err;
if (*old_vers_heap) {
mem_heap_empty(*old_vers_heap);
} else {
*old_vers_heap = mem_heap_create(512);
}
err = row_vers_build_for_consistent_read(
rec, mtr, index, offsets, read_view, offset_heap,
*old_vers_heap, old_vers);
return(err);
}
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/*********************************************************************//**
Builds the last committed version of a clustered index record for a
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semi-consistent read. */
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static MY_ATTRIBUTE((nonnull))
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void
row_sel_build_committed_vers_for_mysql(
/*===================================*/
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dict_index_t* clust_index, /*!< in: clustered index */
row_prebuilt_t* prebuilt, /*!< in: prebuilt struct */
const rec_t* rec, /*!< in: record in a clustered index */
ulint** offsets, /*!< in/out: offsets returned by
rec_get_offsets(rec, clust_index) */
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mem_heap_t** offset_heap, /*!< in/out: memory heap from which
the offsets are allocated */
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const rec_t** old_vers, /*!< out: old version, or NULL if the
record does not exist in the view:
i.e., it was freshly inserted
afterwards */
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mtr_t* mtr) /*!< in: mtr */
{
if (prebuilt->old_vers_heap) {
mem_heap_empty(prebuilt->old_vers_heap);
} else {
2013-12-16 15:38:05 +01:00
prebuilt->old_vers_heap = mem_heap_create(
rec_offs_size(*offsets));
}
2013-12-16 15:38:05 +01:00
row_vers_build_for_semi_consistent_read(
rec, mtr, clust_index, offsets, offset_heap,
prebuilt->old_vers_heap, old_vers);
}
2009-09-07 12:22:53 +02:00
/*********************************************************************//**
Tests the conditions which determine when the index segment we are searching
2009-09-07 12:22:53 +02:00
through has been exhausted.
@return TRUE if row passed the tests */
UNIV_INLINE
ibool
row_sel_test_end_conds(
/*===================*/
2009-09-07 12:22:53 +02:00
plan_t* plan) /*!< in: plan for the table; the column values must
already have been retrieved and the right sides of
comparisons evaluated */
{
func_node_t* cond;
/* All conditions in end_conds are comparisons of a column to an
expression */
2013-12-16 15:38:05 +01:00
for (cond = UT_LIST_GET_FIRST(plan->end_conds);
cond != 0;
cond = UT_LIST_GET_NEXT(cond_list, cond)) {
/* Evaluate the left side of the comparison, i.e., get the
column value if there is an indirection */
2013-12-16 15:38:05 +01:00
eval_sym(static_cast<sym_node_t*>(cond->args));
/* Do the comparison */
if (!eval_cmp(cond)) {
return(FALSE);
}
}
return(TRUE);
}
2009-09-07 12:22:53 +02:00
/*********************************************************************//**
Tests the other conditions.
@return TRUE if row passed the tests */
UNIV_INLINE
ibool
row_sel_test_other_conds(
/*=====================*/
2009-09-07 12:22:53 +02:00
plan_t* plan) /*!< in: plan for the table; the column values must
already have been retrieved */
{
func_node_t* cond;
cond = UT_LIST_GET_FIRST(plan->other_conds);
while (cond) {
eval_exp(cond);
if (!eval_node_get_ibool_val(cond)) {
return(FALSE);
}
cond = UT_LIST_GET_NEXT(cond_list, cond);
}
return(TRUE);
}
2009-09-07 12:22:53 +02:00
/*********************************************************************//**
Retrieves the clustered index record corresponding to a record in a
2009-09-07 12:22:53 +02:00
non-clustered index. Does the necessary locking.
@return DB_SUCCESS or error code */
2016-08-10 19:24:58 +02:00
static MY_ATTRIBUTE((nonnull, warn_unused_result))
2013-12-16 15:38:05 +01:00
dberr_t
row_sel_get_clust_rec(
/*==================*/
2009-09-07 12:22:53 +02:00
sel_node_t* node, /*!< in: select_node */
plan_t* plan, /*!< in: plan node for table */
rec_t* rec, /*!< in: record in a non-clustered index */
que_thr_t* thr, /*!< in: query thread */
rec_t** out_rec,/*!< out: clustered record or an old version of
it, NULL if the old version did not exist
in the read view, i.e., it was a fresh
inserted version */
2009-09-07 12:22:53 +02:00
mtr_t* mtr) /*!< in: mtr used to get access to the
non-clustered record; the same mtr is used to
access the clustered index */
{
dict_index_t* index;
rec_t* clust_rec;
rec_t* old_vers;
2013-12-16 15:38:05 +01:00
dberr_t err;
mem_heap_t* heap = NULL;
ulint offsets_[REC_OFFS_NORMAL_SIZE];
ulint* offsets = offsets_;
rec_offs_init(offsets_);
*out_rec = NULL;
offsets = rec_get_offsets(rec,
btr_pcur_get_btr_cur(&plan->pcur)->index,
offsets, ULINT_UNDEFINED, &heap);
row_build_row_ref_fast(plan->clust_ref, plan->clust_map, rec, offsets);
index = dict_table_get_first_index(plan->table);
btr_pcur_open_with_no_init(index, plan->clust_ref, PAGE_CUR_LE,
2009-03-26 07:11:11 +01:00
BTR_SEARCH_LEAF, &plan->clust_pcur,
0, mtr);
clust_rec = btr_pcur_get_rec(&(plan->clust_pcur));
/* Note: only if the search ends up on a non-infimum record is the
low_match value the real match to the search tuple */
if (!page_rec_is_user_rec(clust_rec)
|| btr_pcur_get_low_match(&(plan->clust_pcur))
< dict_index_get_n_unique(index)) {
ut_a(rec_get_deleted_flag(rec,
dict_table_is_comp(plan->table)));
ut_a(node->read_view);
/* In a rare case it is possible that no clust rec is found
2013-12-16 15:38:05 +01:00
for a delete-marked secondary index record: if in row0umod.cc
in row_undo_mod_remove_clust_low() we have already removed
the clust rec, while purge is still cleaning and removing
secondary index records associated with earlier versions of
the clustered index record. In that case we know that the
clustered index record did not exist in the read view of
trx. */
goto func_exit;
}
offsets = rec_get_offsets(clust_rec, index, offsets,
ULINT_UNDEFINED, &heap);
if (!node->read_view) {
/* Try to place a lock on the index record */
ulint lock_type;
trx_t* trx;
trx = thr_get_trx(thr);
/* If innodb_locks_unsafe_for_binlog option is used
or this session is using READ COMMITTED or lower isolation level
we lock only the record, i.e., next-key locking is
not used. */
if (srv_locks_unsafe_for_binlog
|| trx->isolation_level <= TRX_ISO_READ_COMMITTED) {
lock_type = LOCK_REC_NOT_GAP;
} else {
lock_type = LOCK_ORDINARY;
}
err = lock_clust_rec_read_check_and_lock(
0, btr_pcur_get_block(&plan->clust_pcur),
clust_rec, index, offsets,
2013-12-16 15:38:05 +01:00
static_cast<enum lock_mode>(node->row_lock_mode),
lock_type,
thr);
switch (err) {
case DB_SUCCESS:
case DB_SUCCESS_LOCKED_REC:
/* Declare the variable uninitialized in Valgrind.
It should be set to DB_SUCCESS at func_exit. */
UNIV_MEM_INVALID(&err, sizeof err);
break;
default:
goto err_exit;
}
} else {
/* This is a non-locking consistent read: if necessary, fetch
a previous version of the record */
old_vers = NULL;
if (!lock_clust_rec_cons_read_sees(clust_rec, index, offsets,
node->read_view)) {
err = row_sel_build_prev_vers(
node->read_view, index, clust_rec,
&offsets, &heap, &plan->old_vers_heap,
&old_vers, mtr);
if (err != DB_SUCCESS) {
goto err_exit;
}
clust_rec = old_vers;
if (clust_rec == NULL) {
goto func_exit;
}
}
/* If we had to go to an earlier version of row or the
secondary index record is delete marked, then it may be that
the secondary index record corresponding to clust_rec
(or old_vers) is not rec; in that case we must ignore
such row because in our snapshot rec would not have existed.
Remember that from rec we cannot see directly which transaction
id corresponds to it: we have to go to the clustered index
record. A query where we want to fetch all rows where
the secondary index value is in some interval would return
a wrong result if we would not drop rows which we come to
visit through secondary index records that would not really
exist in our snapshot. */
if ((old_vers
|| rec_get_deleted_flag(rec, dict_table_is_comp(
plan->table)))
&& !row_sel_sec_rec_is_for_clust_rec(rec, plan->index,
clust_rec, index)) {
goto func_exit;
}
}
/* Fetch the columns needed in test conditions. The clustered
index record is protected by a page latch that was acquired
when plan->clust_pcur was positioned. The latch will not be
released until mtr_commit(mtr). */
ut_ad(!rec_get_deleted_flag(clust_rec, rec_offs_comp(offsets)));
row_sel_fetch_columns(index, clust_rec, offsets,
UT_LIST_GET_FIRST(plan->columns));
*out_rec = clust_rec;
func_exit:
err = DB_SUCCESS;
err_exit:
if (UNIV_LIKELY_NULL(heap)) {
mem_heap_free(heap);
}
return(err);
}
2009-09-07 12:22:53 +02:00
/*********************************************************************//**
Sets a lock on a record.
@return DB_SUCCESS, DB_SUCCESS_LOCKED_REC, or error code */
UNIV_INLINE
2013-12-16 15:38:05 +01:00
dberr_t
sel_set_rec_lock(
/*=============*/
2009-09-07 12:22:53 +02:00
const buf_block_t* block, /*!< in: buffer block of rec */
const rec_t* rec, /*!< in: record */
dict_index_t* index, /*!< in: index */
const ulint* offsets,/*!< in: rec_get_offsets(rec, index) */
ulint mode, /*!< in: lock mode */
ulint type, /*!< in: LOCK_ORDINARY, LOCK_GAP, or
LOC_REC_NOT_GAP */
2009-09-07 12:22:53 +02:00
que_thr_t* thr) /*!< in: query thread */
{
trx_t* trx;
2013-12-16 15:38:05 +01:00
dberr_t err;
trx = thr_get_trx(thr);
2013-12-16 15:38:05 +01:00
if (UT_LIST_GET_LEN(trx->lock.trx_locks) > 10000) {
if (buf_LRU_buf_pool_running_out()) {
return(DB_LOCK_TABLE_FULL);
}
}
if (dict_index_is_clust(index)) {
err = lock_clust_rec_read_check_and_lock(
2013-12-16 15:38:05 +01:00
0, block, rec, index, offsets,
static_cast<enum lock_mode>(mode), type, thr);
} else {
err = lock_sec_rec_read_check_and_lock(
2013-12-16 15:38:05 +01:00
0, block, rec, index, offsets,
static_cast<enum lock_mode>(mode), type, thr);
}
return(err);
}
2009-09-07 12:22:53 +02:00
/*********************************************************************//**
Opens a pcur to a table index. */
static
void
row_sel_open_pcur(
/*==============*/
2009-09-07 12:22:53 +02:00
plan_t* plan, /*!< in: table plan */
ibool search_latch_locked,
2009-09-07 12:22:53 +02:00
/*!< in: TRUE if the thread currently
has the search latch locked in
s-mode */
2009-09-07 12:22:53 +02:00
mtr_t* mtr) /*!< in: mtr */
{
dict_index_t* index;
func_node_t* cond;
que_node_t* exp;
ulint n_fields;
ulint has_search_latch = 0; /* RW_S_LATCH or 0 */
ulint i;
if (search_latch_locked) {
has_search_latch = RW_S_LATCH;
}
index = plan->index;
/* Calculate the value of the search tuple: the exact match columns
get their expressions evaluated when we evaluate the right sides of
end_conds */
cond = UT_LIST_GET_FIRST(plan->end_conds);
while (cond) {
eval_exp(que_node_get_next(cond->args));
cond = UT_LIST_GET_NEXT(cond_list, cond);
}
if (plan->tuple) {
n_fields = dtuple_get_n_fields(plan->tuple);
if (plan->n_exact_match < n_fields) {
/* There is a non-exact match field which must be
evaluated separately */
eval_exp(plan->tuple_exps[n_fields - 1]);
}
for (i = 0; i < n_fields; i++) {
exp = plan->tuple_exps[i];
dfield_copy_data(dtuple_get_nth_field(plan->tuple, i),
que_node_get_val(exp));
}
/* Open pcur to the index */
btr_pcur_open_with_no_init(index, plan->tuple, plan->mode,
2009-03-26 07:11:11 +01:00
BTR_SEARCH_LEAF, &plan->pcur,
has_search_latch, mtr);
} else {
/* Open the cursor to the start or the end of the index
(FALSE: no init) */
2009-03-26 07:11:11 +01:00
btr_pcur_open_at_index_side(plan->asc, index, BTR_SEARCH_LEAF,
2013-12-16 15:38:05 +01:00
&(plan->pcur), false, 0, mtr);
}
ut_ad(plan->n_rows_prefetched == 0);
ut_ad(plan->n_rows_fetched == 0);
ut_ad(plan->cursor_at_end == FALSE);
plan->pcur_is_open = TRUE;
}
2009-09-07 12:22:53 +02:00
/*********************************************************************//**
Restores a stored pcur position to a table index.
@return TRUE if the cursor should be moved to the next record after we
return from this function (moved to the previous, in the case of a
descending cursor) without processing again the current cursor
record */
static
ibool
row_sel_restore_pcur_pos(
/*=====================*/
2009-09-07 12:22:53 +02:00
plan_t* plan, /*!< in: table plan */
mtr_t* mtr) /*!< in: mtr */
{
ibool equal_position;
ulint relative_position;
ut_ad(!plan->cursor_at_end);
relative_position = btr_pcur_get_rel_pos(&(plan->pcur));
2009-03-26 07:11:11 +01:00
equal_position = btr_pcur_restore_position(BTR_SEARCH_LEAF,
&(plan->pcur), mtr);
/* If the cursor is traveling upwards, and relative_position is
(1) BTR_PCUR_BEFORE: this is not allowed, as we did not have a lock
yet on the successor of the page infimum;
(2) BTR_PCUR_AFTER: btr_pcur_restore_position placed the cursor on the
first record GREATER than the predecessor of a page supremum; we have
not yet processed the cursor record: no need to move the cursor to the
next record;
(3) BTR_PCUR_ON: btr_pcur_restore_position placed the cursor on the
last record LESS or EQUAL to the old stored user record; (a) if
equal_position is FALSE, this means that the cursor is now on a record
less than the old user record, and we must move to the next record;
(b) if equal_position is TRUE, then if
plan->stored_cursor_rec_processed is TRUE, we must move to the next
record, else there is no need to move the cursor. */
if (plan->asc) {
if (relative_position == BTR_PCUR_ON) {
if (equal_position) {
return(plan->stored_cursor_rec_processed);
}
return(TRUE);
}
ut_ad(relative_position == BTR_PCUR_AFTER
|| relative_position == BTR_PCUR_AFTER_LAST_IN_TREE);
return(FALSE);
}
/* If the cursor is traveling downwards, and relative_position is
(1) BTR_PCUR_BEFORE: btr_pcur_restore_position placed the cursor on
the last record LESS than the successor of a page infimum; we have not
processed the cursor record: no need to move the cursor;
(2) BTR_PCUR_AFTER: btr_pcur_restore_position placed the cursor on the
first record GREATER than the predecessor of a page supremum; we have
processed the cursor record: we should move the cursor to the previous
record;
(3) BTR_PCUR_ON: btr_pcur_restore_position placed the cursor on the
last record LESS or EQUAL to the old stored user record; (a) if
equal_position is FALSE, this means that the cursor is now on a record
less than the old user record, and we need not move to the previous
record; (b) if equal_position is TRUE, then if
plan->stored_cursor_rec_processed is TRUE, we must move to the previous
record, else there is no need to move the cursor. */
if (relative_position == BTR_PCUR_BEFORE
|| relative_position == BTR_PCUR_BEFORE_FIRST_IN_TREE) {
return(FALSE);
}
if (relative_position == BTR_PCUR_ON) {
if (equal_position) {
return(plan->stored_cursor_rec_processed);
}
return(FALSE);
}
ut_ad(relative_position == BTR_PCUR_AFTER
|| relative_position == BTR_PCUR_AFTER_LAST_IN_TREE);
return(TRUE);
}
2009-09-07 12:22:53 +02:00
/*********************************************************************//**
Resets a plan cursor to a closed state. */
UNIV_INLINE
void
plan_reset_cursor(
/*==============*/
2009-09-07 12:22:53 +02:00
plan_t* plan) /*!< in: plan */
{
plan->pcur_is_open = FALSE;
plan->cursor_at_end = FALSE;
plan->n_rows_fetched = 0;
plan->n_rows_prefetched = 0;
}
2009-09-07 12:22:53 +02:00
/*********************************************************************//**
Tries to do a shortcut to fetch a clustered index record with a unique key,
2009-09-07 12:22:53 +02:00
using the hash index if possible (not always).
@return SEL_FOUND, SEL_EXHAUSTED, SEL_RETRY */
static
ulint
row_sel_try_search_shortcut(
/*========================*/
2009-09-07 12:22:53 +02:00
sel_node_t* node, /*!< in: select node for a consistent read */
plan_t* plan, /*!< in: plan for a unique search in clustered
index */
2013-12-16 15:38:05 +01:00
ibool search_latch_locked,
/*!< in: whether the search holds
btr_search_latch */
2009-09-07 12:22:53 +02:00
mtr_t* mtr) /*!< in: mtr */
{
dict_index_t* index;
rec_t* rec;
mem_heap_t* heap = NULL;
ulint offsets_[REC_OFFS_NORMAL_SIZE];
ulint* offsets = offsets_;
ulint ret;
rec_offs_init(offsets_);
index = plan->index;
ut_ad(node->read_view);
ut_ad(plan->unique_search);
ut_ad(!plan->must_get_clust);
#ifdef UNIV_SYNC_DEBUG
2013-12-16 15:38:05 +01:00
if (search_latch_locked) {
ut_ad(rw_lock_own(btr_search_get_latch(index),
RW_LOCK_SHARED));
}
#endif /* UNIV_SYNC_DEBUG */
2013-12-16 15:38:05 +01:00
row_sel_open_pcur(plan, search_latch_locked, mtr);
rec = btr_pcur_get_rec(&(plan->pcur));
if (!page_rec_is_user_rec(rec)) {
return(SEL_RETRY);
}
ut_ad(plan->mode == PAGE_CUR_GE);
/* As the cursor is now placed on a user record after a search with
the mode PAGE_CUR_GE, the up_match field in the cursor tells how many
fields in the user record matched to the search tuple */
if (btr_pcur_get_up_match(&(plan->pcur)) < plan->n_exact_match) {
return(SEL_EXHAUSTED);
}
/* This is a non-locking consistent read: if necessary, fetch
a previous version of the record */
offsets = rec_get_offsets(rec, index, offsets, ULINT_UNDEFINED, &heap);
if (dict_index_is_clust(index)) {
if (!lock_clust_rec_cons_read_sees(rec, index, offsets,
node->read_view)) {
ret = SEL_RETRY;
goto func_exit;
}
} else if (!lock_sec_rec_cons_read_sees(rec, node->read_view)) {
ret = SEL_RETRY;
goto func_exit;
}
/* Test the deleted flag. */
if (rec_get_deleted_flag(rec, dict_table_is_comp(plan->table))) {
ret = SEL_EXHAUSTED;
goto func_exit;
}
/* Fetch the columns needed in test conditions. The index
record is protected by a page latch that was acquired when
plan->pcur was positioned. The latch will not be released
until mtr_commit(mtr). */
row_sel_fetch_columns(index, rec, offsets,
UT_LIST_GET_FIRST(plan->columns));
/* Test the rest of search conditions */
if (!row_sel_test_other_conds(plan)) {
ret = SEL_EXHAUSTED;
goto func_exit;
}
2009-03-26 07:11:11 +01:00
ut_ad(plan->pcur.latch_mode == BTR_SEARCH_LEAF);
plan->n_rows_fetched++;
ret = SEL_FOUND;
func_exit:
if (UNIV_LIKELY_NULL(heap)) {
mem_heap_free(heap);
}
return(ret);
}
2009-09-07 12:22:53 +02:00
/*********************************************************************//**
Performs a select step.
@return DB_SUCCESS or error code */
2016-08-10 19:24:58 +02:00
static MY_ATTRIBUTE((nonnull, warn_unused_result))
2013-12-16 15:38:05 +01:00
dberr_t
row_sel(
/*====*/
2009-09-07 12:22:53 +02:00
sel_node_t* node, /*!< in: select node */
que_thr_t* thr) /*!< in: query thread */
{
dict_index_t* index;
plan_t* plan;
mtr_t mtr;
ibool moved;
rec_t* rec;
rec_t* old_vers;
rec_t* clust_rec;
ibool search_latch_locked;
ibool consistent_read;
/* The following flag becomes TRUE when we are doing a
consistent read from a non-clustered index and we must look
at the clustered index to find out the previous delete mark
state of the non-clustered record: */
ibool cons_read_requires_clust_rec = FALSE;
ulint cost_counter = 0;
ibool cursor_just_opened;
ibool must_go_to_next;
ibool mtr_has_extra_clust_latch = FALSE;
/* TRUE if the search was made using
a non-clustered index, and we had to
access the clustered record: now &mtr
contains a clustered index latch, and
&mtr must be committed before we move
to the next non-clustered record */
ulint found_flag;
2013-12-16 15:38:05 +01:00
dberr_t err;
mem_heap_t* heap = NULL;
ulint offsets_[REC_OFFS_NORMAL_SIZE];
ulint* offsets = offsets_;
rec_offs_init(offsets_);
ut_ad(thr->run_node == node);
search_latch_locked = FALSE;
if (node->read_view) {
/* In consistent reads, we try to do with the hash index and
not to use the buffer page get. This is to reduce memory bus
load resulting from semaphore operations. The search latch
will be s-locked when we access an index with a unique search
condition, but not locked when we access an index with a
less selective search condition. */
consistent_read = TRUE;
} else {
consistent_read = FALSE;
}
table_loop:
/* TABLE LOOP
----------
This is the outer major loop in calculating a join. We come here when
node->fetch_table changes, and after adding a row to aggregate totals
and, of course, when this function is called. */
ut_ad(mtr_has_extra_clust_latch == FALSE);
plan = sel_node_get_nth_plan(node, node->fetch_table);
index = plan->index;
if (plan->n_rows_prefetched > 0) {
2013-12-16 15:38:05 +01:00
sel_dequeue_prefetched_row(plan);
goto next_table_no_mtr;
}
if (plan->cursor_at_end) {
/* The cursor has already reached the result set end: no more
rows to process for this table cursor, as also the prefetch
stack was empty */
ut_ad(plan->pcur_is_open);
goto table_exhausted_no_mtr;
}
/* Open a cursor to index, or restore an open cursor position */
mtr_start_trx(&mtr, thr_get_trx(thr));
if (consistent_read && plan->unique_search && !plan->pcur_is_open
&& !plan->must_get_clust
&& !plan->table->big_rows) {
if (!search_latch_locked) {
2013-11-07 21:44:46 +01:00
rw_lock_s_lock(btr_search_get_latch(index));
search_latch_locked = TRUE;
2013-11-07 21:44:46 +01:00
} else if (rw_lock_get_writer(btr_search_get_latch(index))
== RW_LOCK_WAIT_EX) {
/* There is an x-latch request waiting: release the
s-latch for a moment; as an s-latch here is often
kept for some 10 searches before being released,
a waiting x-latch request would block other threads
from acquiring an s-latch for a long time, lowering
performance significantly in multiprocessors. */
2013-11-07 21:44:46 +01:00
rw_lock_s_unlock(btr_search_get_latch(index));
rw_lock_s_lock(btr_search_get_latch(index));
}
2013-12-16 15:38:05 +01:00
found_flag = row_sel_try_search_shortcut(node, plan,
search_latch_locked,
&mtr);
if (found_flag == SEL_FOUND) {
goto next_table;
} else if (found_flag == SEL_EXHAUSTED) {
goto table_exhausted;
}
ut_ad(found_flag == SEL_RETRY);
plan_reset_cursor(plan);
mtr_commit(&mtr);
mtr_start_trx(&mtr, thr_get_trx(thr));
}
if (search_latch_locked) {
2013-11-07 21:44:46 +01:00
rw_lock_s_unlock(btr_search_get_latch(index));
search_latch_locked = FALSE;
}
if (!plan->pcur_is_open) {
/* Evaluate the expressions to build the search tuple and
open the cursor */
2009-03-26 07:11:11 +01:00
row_sel_open_pcur(plan, search_latch_locked, &mtr);
cursor_just_opened = TRUE;
/* A new search was made: increment the cost counter */
cost_counter++;
} else {
/* Restore pcur position to the index */
2009-03-26 07:11:11 +01:00
must_go_to_next = row_sel_restore_pcur_pos(plan, &mtr);
cursor_just_opened = FALSE;
if (must_go_to_next) {
/* We have already processed the cursor record: move
to the next */
goto next_rec;
}
}
rec_loop:
/* RECORD LOOP
-----------
In this loop we use pcur and try to fetch a qualifying row, and
also fill the prefetch buffer for this table if n_rows_fetched has
exceeded a threshold. While we are inside this loop, the following
holds:
(1) &mtr is started,
(2) pcur is positioned and open.
NOTE that if cursor_just_opened is TRUE here, it means that we came
to this point right after row_sel_open_pcur. */
ut_ad(mtr_has_extra_clust_latch == FALSE);
rec = btr_pcur_get_rec(&(plan->pcur));
/* PHASE 1: Set a lock if specified */
if (!node->asc && cursor_just_opened
&& !page_rec_is_supremum(rec)) {
/* When we open a cursor for a descending search, we must set
a next-key lock on the successor record: otherwise it would
be possible to insert new records next to the cursor position,
and it might be that these new records should appear in the
search result set, resulting in the phantom problem. */
if (!consistent_read) {
rec_t* next_rec = page_rec_get_next(rec);
ulint lock_type;
trx_t* trx;
trx = thr_get_trx(thr);
offsets = rec_get_offsets(next_rec, index, offsets,
ULINT_UNDEFINED, &heap);
/* If innodb_locks_unsafe_for_binlog option is used
or this session is using READ COMMITTED or lower isolation
level, we lock only the record, i.e., next-key
locking is not used. */
if (srv_locks_unsafe_for_binlog
|| trx->isolation_level
<= TRX_ISO_READ_COMMITTED) {
if (page_rec_is_supremum(next_rec)) {
goto skip_lock;
}
lock_type = LOCK_REC_NOT_GAP;
} else {
lock_type = LOCK_ORDINARY;
}
err = sel_set_rec_lock(btr_pcur_get_block(&plan->pcur),
next_rec, index, offsets,
node->row_lock_mode,
lock_type, thr);
switch (err) {
case DB_SUCCESS_LOCKED_REC:
err = DB_SUCCESS;
case DB_SUCCESS:
break;
default:
/* Note that in this case we will store in pcur
the PREDECESSOR of the record we are waiting
the lock for */
goto lock_wait_or_error;
}
}
}
skip_lock:
if (page_rec_is_infimum(rec)) {
/* The infimum record on a page cannot be in the result set,
and neither can a record lock be placed on it: we skip such
a record. We also increment the cost counter as we may have
processed yet another page of index. */
cost_counter++;
goto next_rec;
}
if (!consistent_read) {
/* Try to place a lock on the index record */
ulint lock_type;
trx_t* trx;
offsets = rec_get_offsets(rec, index, offsets,
ULINT_UNDEFINED, &heap);
trx = thr_get_trx(thr);
/* If innodb_locks_unsafe_for_binlog option is used
or this session is using READ COMMITTED or lower isolation level,
we lock only the record, i.e., next-key locking is
not used. */
if (srv_locks_unsafe_for_binlog
|| trx->isolation_level <= TRX_ISO_READ_COMMITTED) {
if (page_rec_is_supremum(rec)) {
goto next_rec;
}
lock_type = LOCK_REC_NOT_GAP;
} else {
lock_type = LOCK_ORDINARY;
}
err = sel_set_rec_lock(btr_pcur_get_block(&plan->pcur),
rec, index, offsets,
node->row_lock_mode, lock_type, thr);
switch (err) {
case DB_SUCCESS_LOCKED_REC:
err = DB_SUCCESS;
case DB_SUCCESS:
break;
default:
goto lock_wait_or_error;
}
}
if (page_rec_is_supremum(rec)) {
/* A page supremum record cannot be in the result set: skip
it now when we have placed a possible lock on it */
goto next_rec;
}
ut_ad(page_rec_is_user_rec(rec));
if (cost_counter > SEL_COST_LIMIT) {
/* Now that we have placed the necessary locks, we can stop
for a while and store the cursor position; NOTE that if we
would store the cursor position BEFORE placing a record lock,
it might happen that the cursor would jump over some records
that another transaction could meanwhile insert adjacent to
the cursor: this would result in the phantom problem. */
goto stop_for_a_while;
}
/* PHASE 2: Check a mixed index mix id if needed */
if (plan->unique_search && cursor_just_opened) {
ut_ad(plan->mode == PAGE_CUR_GE);
/* As the cursor is now placed on a user record after a search
with the mode PAGE_CUR_GE, the up_match field in the cursor
tells how many fields in the user record matched to the search
tuple */
if (btr_pcur_get_up_match(&(plan->pcur))
< plan->n_exact_match) {
goto table_exhausted;
}
/* Ok, no need to test end_conds or mix id */
}
/* We are ready to look at a possible new index entry in the result
set: the cursor is now placed on a user record */
/* PHASE 3: Get previous version in a consistent read */
cons_read_requires_clust_rec = FALSE;
offsets = rec_get_offsets(rec, index, offsets, ULINT_UNDEFINED, &heap);
if (consistent_read) {
/* This is a non-locking consistent read: if necessary, fetch
a previous version of the record */
if (dict_index_is_clust(index)) {
if (!lock_clust_rec_cons_read_sees(rec, index, offsets,
node->read_view)) {
err = row_sel_build_prev_vers(
node->read_view, index, rec,
&offsets, &heap, &plan->old_vers_heap,
&old_vers, &mtr);
if (err != DB_SUCCESS) {
goto lock_wait_or_error;
}
if (old_vers == NULL) {
/* The record does not exist
in our read view. Skip it, but
first attempt to determine
whether the index segment we
are searching through has been
exhausted. */
offsets = rec_get_offsets(
rec, index, offsets,
ULINT_UNDEFINED, &heap);
/* Fetch the columns needed in
test conditions. The clustered
index record is protected by a
page latch that was acquired
by row_sel_open_pcur() or
row_sel_restore_pcur_pos().
The latch will not be released
until mtr_commit(mtr). */
row_sel_fetch_columns(
index, rec, offsets,
UT_LIST_GET_FIRST(
plan->columns));
if (!row_sel_test_end_conds(plan)) {
goto table_exhausted;
}
goto next_rec;
}
rec = old_vers;
}
} else if (!lock_sec_rec_cons_read_sees(rec,
node->read_view)) {
cons_read_requires_clust_rec = TRUE;
}
}
/* PHASE 4: Test search end conditions and deleted flag */
/* Fetch the columns needed in test conditions. The record is
protected by a page latch that was acquired by
row_sel_open_pcur() or row_sel_restore_pcur_pos(). The latch
will not be released until mtr_commit(mtr). */
row_sel_fetch_columns(index, rec, offsets,
UT_LIST_GET_FIRST(plan->columns));
/* Test the selection end conditions: these can only contain columns
which already are found in the index, even though the index might be
non-clustered */
if (plan->unique_search && cursor_just_opened) {
/* No test necessary: the test was already made above */
} else if (!row_sel_test_end_conds(plan)) {
goto table_exhausted;
}
if (rec_get_deleted_flag(rec, dict_table_is_comp(plan->table))
&& !cons_read_requires_clust_rec) {
/* The record is delete marked: we can skip it if this is
not a consistent read which might see an earlier version
of a non-clustered index record */
if (plan->unique_search) {
goto table_exhausted;
}
goto next_rec;
}
/* PHASE 5: Get the clustered index record, if needed and if we did
not do the search using the clustered index */
if (plan->must_get_clust || cons_read_requires_clust_rec) {
/* It was a non-clustered index and we must fetch also the
clustered index record */
err = row_sel_get_clust_rec(node, plan, rec, thr, &clust_rec,
&mtr);
mtr_has_extra_clust_latch = TRUE;
if (err != DB_SUCCESS) {
goto lock_wait_or_error;
}
/* Retrieving the clustered record required a search:
increment the cost counter */
cost_counter++;
if (clust_rec == NULL) {
/* The record did not exist in the read view */
ut_ad(consistent_read);
goto next_rec;
}
if (rec_get_deleted_flag(clust_rec,
dict_table_is_comp(plan->table))) {
/* The record is delete marked: we can skip it */
goto next_rec;
}
if (node->can_get_updated) {
btr_pcur_store_position(&(plan->clust_pcur), &mtr);
}
}
/* PHASE 6: Test the rest of search conditions */
if (!row_sel_test_other_conds(plan)) {
if (plan->unique_search) {
goto table_exhausted;
}
goto next_rec;
}
/* PHASE 7: We found a new qualifying row for the current table; push
the row if prefetch is on, or move to the next table in the join */
plan->n_rows_fetched++;
2009-03-26 07:11:11 +01:00
ut_ad(plan->pcur.latch_mode == BTR_SEARCH_LEAF);
if ((plan->n_rows_fetched <= SEL_PREFETCH_LIMIT)
|| plan->unique_search || plan->no_prefetch
|| plan->table->big_rows) {
/* No prefetch in operation: go to the next table */
goto next_table;
}
2013-12-16 15:38:05 +01:00
sel_enqueue_prefetched_row(plan);
if (plan->n_rows_prefetched == SEL_MAX_N_PREFETCH) {
/* The prefetch buffer is now full */
2013-12-16 15:38:05 +01:00
sel_dequeue_prefetched_row(plan);
goto next_table;
}
next_rec:
ut_ad(!search_latch_locked);
if (mtr_has_extra_clust_latch) {
/* We must commit &mtr if we are moving to the next
non-clustered index record, because we could break the
latching order if we would access a different clustered
index page right away without releasing the previous. */
goto commit_mtr_for_a_while;
}
if (node->asc) {
moved = btr_pcur_move_to_next(&(plan->pcur), &mtr);
} else {
moved = btr_pcur_move_to_prev(&(plan->pcur), &mtr);
}
if (!moved) {
goto table_exhausted;
}
cursor_just_opened = FALSE;
/* END OF RECORD LOOP
------------------ */
goto rec_loop;
next_table:
/* We found a record which satisfies the conditions: we can move to
the next table or return a row in the result set */
ut_ad(btr_pcur_is_on_user_rec(&plan->pcur));
if (plan->unique_search && !node->can_get_updated) {
plan->cursor_at_end = TRUE;
} else {
ut_ad(!search_latch_locked);
plan->stored_cursor_rec_processed = TRUE;
btr_pcur_store_position(&(plan->pcur), &mtr);
}
mtr_commit(&mtr);
mtr_has_extra_clust_latch = FALSE;
next_table_no_mtr:
/* If we use 'goto' to this label, it means that the row was popped
from the prefetched rows stack, and &mtr is already committed */
if (node->fetch_table + 1 == node->n_tables) {
sel_eval_select_list(node);
if (node->is_aggregate) {
goto table_loop;
}
sel_assign_into_var_values(node->into_list, node);
thr->run_node = que_node_get_parent(node);
err = DB_SUCCESS;
goto func_exit;
}
node->fetch_table++;
/* When we move to the next table, we first reset the plan cursor:
we do not care about resetting it when we backtrack from a table */
plan_reset_cursor(sel_node_get_nth_plan(node, node->fetch_table));
goto table_loop;
table_exhausted:
/* The table cursor pcur reached the result set end: backtrack to the
previous table in the join if we do not have cached prefetched rows */
plan->cursor_at_end = TRUE;
mtr_commit(&mtr);
mtr_has_extra_clust_latch = FALSE;
if (plan->n_rows_prefetched > 0) {
/* The table became exhausted during a prefetch */
2013-12-16 15:38:05 +01:00
sel_dequeue_prefetched_row(plan);
goto next_table_no_mtr;
}
table_exhausted_no_mtr:
if (node->fetch_table == 0) {
err = DB_SUCCESS;
if (node->is_aggregate && !node->aggregate_already_fetched) {
node->aggregate_already_fetched = TRUE;
sel_assign_into_var_values(node->into_list, node);
thr->run_node = que_node_get_parent(node);
} else {
node->state = SEL_NODE_NO_MORE_ROWS;
thr->run_node = que_node_get_parent(node);
}
goto func_exit;
}
node->fetch_table--;
goto table_loop;
stop_for_a_while:
/* Return control for a while to que_run_threads, so that runaway
queries can be canceled. NOTE that when we come here, we must, in a
locking read, have placed the necessary (possibly waiting request)
record lock on the cursor record or its successor: when we reposition
the cursor, this record lock guarantees that nobody can meanwhile have
inserted new records which should have appeared in the result set,
which would result in the phantom problem. */
ut_ad(!search_latch_locked);
plan->stored_cursor_rec_processed = FALSE;
btr_pcur_store_position(&(plan->pcur), &mtr);
mtr_commit(&mtr);
#ifdef UNIV_SYNC_DEBUG
2011-07-14 21:22:41 +02:00
ut_ad(sync_thread_levels_empty_except_dict());
#endif /* UNIV_SYNC_DEBUG */
err = DB_SUCCESS;
goto func_exit;
commit_mtr_for_a_while:
/* Stores the cursor position and commits &mtr; this is used if
&mtr may contain latches which would break the latching order if
&mtr would not be committed and the latches released. */
plan->stored_cursor_rec_processed = TRUE;
ut_ad(!search_latch_locked);
btr_pcur_store_position(&(plan->pcur), &mtr);
mtr_commit(&mtr);
mtr_has_extra_clust_latch = FALSE;
#ifdef UNIV_SYNC_DEBUG
2011-07-14 21:22:41 +02:00
ut_ad(sync_thread_levels_empty_except_dict());
#endif /* UNIV_SYNC_DEBUG */
goto table_loop;
lock_wait_or_error:
/* See the note at stop_for_a_while: the same holds for this case */
ut_ad(!btr_pcur_is_before_first_on_page(&plan->pcur) || !node->asc);
ut_ad(!search_latch_locked);
plan->stored_cursor_rec_processed = FALSE;
btr_pcur_store_position(&(plan->pcur), &mtr);
mtr_commit(&mtr);
#ifdef UNIV_SYNC_DEBUG
2011-07-14 21:22:41 +02:00
ut_ad(sync_thread_levels_empty_except_dict());
#endif /* UNIV_SYNC_DEBUG */
func_exit:
if (search_latch_locked) {
2013-11-07 21:44:46 +01:00
rw_lock_s_unlock(btr_search_get_latch(index));
}
if (UNIV_LIKELY_NULL(heap)) {
mem_heap_free(heap);
}
return(err);
}
2009-09-07 12:22:53 +02:00
/**********************************************************************//**
Performs a select step. This is a high-level function used in SQL execution
2009-09-07 12:22:53 +02:00
graphs.
@return query thread to run next or NULL */
UNIV_INTERN
que_thr_t*
row_sel_step(
/*=========*/
2009-09-07 12:22:53 +02:00
que_thr_t* thr) /*!< in: query thread */
{
sel_node_t* node;
ut_ad(thr);
2013-12-16 15:38:05 +01:00
node = static_cast<sel_node_t*>(thr->run_node);
ut_ad(que_node_get_type(node) == QUE_NODE_SELECT);
/* If this is a new time this node is executed (or when execution
resumes after wait for a table intention lock), set intention locks
on the tables, or assign a read view */
if (node->into_list && (thr->prev_node == que_node_get_parent(node))) {
node->state = SEL_NODE_OPEN;
}
if (node->state == SEL_NODE_OPEN) {
/* It may be that the current session has not yet started
its transaction, or it has been committed: */
2013-12-16 15:38:05 +01:00
trx_start_if_not_started_xa(thr_get_trx(thr));
plan_reset_cursor(sel_node_get_nth_plan(node, 0));
if (node->consistent_read) {
/* Assign a read view for the query */
node->read_view = trx_assign_read_view(
thr_get_trx(thr));
} else {
2013-12-16 15:38:05 +01:00
sym_node_t* table_node;
enum lock_mode i_lock_mode;
if (node->set_x_locks) {
i_lock_mode = LOCK_IX;
} else {
i_lock_mode = LOCK_IS;
}
2013-12-16 15:38:05 +01:00
for (table_node = node->table_list;
table_node != 0;
table_node = static_cast<sym_node_t*>(
que_node_get_next(table_node))) {
dberr_t err = lock_table(
0, table_node->table, i_lock_mode,
thr);
if (err != DB_SUCCESS) {
2013-12-16 15:38:05 +01:00
trx_t* trx;
trx = thr_get_trx(thr);
trx->error_state = err;
return(NULL);
}
}
}
/* If this is an explicit cursor, copy stored procedure
variable values, so that the values cannot change between
fetches (currently, we copy them also for non-explicit
cursors) */
if (node->explicit_cursor
&& UT_LIST_GET_FIRST(node->copy_variables)) {
row_sel_copy_input_variable_vals(node);
}
node->state = SEL_NODE_FETCH;
node->fetch_table = 0;
if (node->is_aggregate) {
/* Reset the aggregate total values */
sel_reset_aggregate_vals(node);
}
}
2013-12-16 15:38:05 +01:00
dberr_t err = row_sel(node, thr);
/* NOTE! if queries are parallelized, the following assignment may
have problems; the assignment should be made only if thr is the
only top-level thr in the graph: */
thr->graph->last_sel_node = node;
if (err != DB_SUCCESS) {
thr_get_trx(thr)->error_state = err;
return(NULL);
}
return(thr);
}
2009-09-07 12:22:53 +02:00
/**********************************************************************//**
Performs a fetch for a cursor.
@return query thread to run next or NULL */
UNIV_INTERN
que_thr_t*
fetch_step(
/*=======*/
2009-09-07 12:22:53 +02:00
que_thr_t* thr) /*!< in: query thread */
{
sel_node_t* sel_node;
fetch_node_t* node;
ut_ad(thr);
2013-12-16 15:38:05 +01:00
node = static_cast<fetch_node_t*>(thr->run_node);
sel_node = node->cursor_def;
ut_ad(que_node_get_type(node) == QUE_NODE_FETCH);
if (thr->prev_node != que_node_get_parent(node)) {
if (sel_node->state != SEL_NODE_NO_MORE_ROWS) {
if (node->into_list) {
sel_assign_into_var_values(node->into_list,
sel_node);
} else {
2013-12-16 15:38:05 +01:00
ibool ret = (*node->func->func)(
sel_node, node->func->arg);
if (!ret) {
sel_node->state
2013-12-16 15:38:05 +01:00
= SEL_NODE_NO_MORE_ROWS;
}
}
}
thr->run_node = que_node_get_parent(node);
return(thr);
}
/* Make the fetch node the parent of the cursor definition for
the time of the fetch, so that execution knows to return to this
fetch node after a row has been selected or we know that there is
no row left */
sel_node->common.parent = node;
if (sel_node->state == SEL_NODE_CLOSED) {
fprintf(stderr,
"InnoDB: Error: fetch called on a closed cursor\n");
thr_get_trx(thr)->error_state = DB_ERROR;
return(NULL);
}
thr->run_node = sel_node;
return(thr);
}
2009-09-07 12:22:53 +02:00
/****************************************************************//**
Sample callback function for fetch that prints each row.
@return always returns non-NULL */
UNIV_INTERN
void*
row_fetch_print(
/*============*/
2009-09-07 12:22:53 +02:00
void* row, /*!< in: sel_node_t* */
void* user_arg) /*!< in: not used */
{
que_node_t* exp;
ulint i = 0;
2013-12-16 15:38:05 +01:00
sel_node_t* node = static_cast<sel_node_t*>(row);
UT_NOT_USED(user_arg);
fprintf(stderr, "row_fetch_print: row %p\n", row);
2013-12-16 15:38:05 +01:00
for (exp = node->select_list;
exp != 0;
exp = que_node_get_next(exp), i++) {
dfield_t* dfield = que_node_get_val(exp);
const dtype_t* type = dfield_get_type(dfield);
2013-12-16 15:38:05 +01:00
fprintf(stderr, " column %lu:\n", (ulong) i);
dtype_print(type);
2008-12-03 06:06:00 +01:00
putc('\n', stderr);
if (dfield_get_len(dfield) != UNIV_SQL_NULL) {
ut_print_buf(stderr, dfield_get_data(dfield),
dfield_get_len(dfield));
2008-12-03 06:06:00 +01:00
putc('\n', stderr);
} else {
2008-12-03 06:06:00 +01:00
fputs(" <NULL>;\n", stderr);
}
}
return((void*)42);
}
2009-09-07 12:22:53 +02:00
/***********************************************************//**
Prints a row in a select result.
@return query thread to run next or NULL */
UNIV_INTERN
que_thr_t*
row_printf_step(
/*============*/
2009-09-07 12:22:53 +02:00
que_thr_t* thr) /*!< in: query thread */
{
row_printf_node_t* node;
sel_node_t* sel_node;
que_node_t* arg;
ut_ad(thr);
2013-12-16 15:38:05 +01:00
node = static_cast<row_printf_node_t*>(thr->run_node);
sel_node = node->sel_node;
ut_ad(que_node_get_type(node) == QUE_NODE_ROW_PRINTF);
if (thr->prev_node == que_node_get_parent(node)) {
/* Reset the cursor */
sel_node->state = SEL_NODE_OPEN;
/* Fetch next row to print */
thr->run_node = sel_node;
return(thr);
}
if (sel_node->state != SEL_NODE_FETCH) {
ut_ad(sel_node->state == SEL_NODE_NO_MORE_ROWS);
/* No more rows to print */
thr->run_node = que_node_get_parent(node);
return(thr);
}
arg = sel_node->select_list;
while (arg) {
dfield_print_also_hex(que_node_get_val(arg));
fputs(" ::: ", stderr);
arg = que_node_get_next(arg);
}
putc('\n', stderr);
/* Fetch next row to print */
thr->run_node = sel_node;
return(thr);
}
2009-09-07 12:22:53 +02:00
/****************************************************************//**
Converts a key value stored in MySQL format to an Innobase dtuple. The last
field of the key value may be just a prefix of a fixed length field: hence
the parameter key_len. But currently we do not allow search keys where the
last field is only a prefix of the full key field len and print a warning if
such appears. A counterpart of this function is
ha_innobase::store_key_val_for_row() in ha_innodb.cc. */
UNIV_INTERN
void
row_sel_convert_mysql_key_to_innobase(
/*==================================*/
2009-09-07 12:22:53 +02:00
dtuple_t* tuple, /*!< in/out: tuple where to build;
NOTE: we assume that the type info
in the tuple is already according
to index! */
2009-09-07 12:22:53 +02:00
byte* buf, /*!< in: buffer to use in field
conversions; NOTE that dtuple->data
may end up pointing inside buf so
do not discard that buffer while
the tuple is being used. See
row_mysql_store_col_in_innobase_format()
in the case of DATA_INT */
2009-09-07 12:22:53 +02:00
ulint buf_len, /*!< in: buffer length */
dict_index_t* index, /*!< in: index of the key value */
const byte* key_ptr, /*!< in: MySQL key value */
ulint key_len, /*!< in: MySQL key value length */
trx_t* trx) /*!< in: transaction */
{
byte* original_buf = buf;
const byte* original_key_ptr = key_ptr;
dict_field_t* field;
dfield_t* dfield;
ulint data_offset;
ulint data_len;
ulint data_field_len;
ibool is_null;
const byte* key_end;
ulint n_fields = 0;
/* For documentation of the key value storage format in MySQL, see
ha_innobase::store_key_val_for_row() in ha_innodb.cc. */
key_end = key_ptr + key_len;
/* Permit us to access any field in the tuple (ULINT_MAX): */
dtuple_set_n_fields(tuple, ULINT_MAX);
dfield = dtuple_get_nth_field(tuple, 0);
field = dict_index_get_nth_field(index, 0);
if (UNIV_UNLIKELY(dfield_get_type(dfield)->mtype == DATA_SYS)) {
/* A special case: we are looking for a position in the
generated clustered index which InnoDB automatically added
to a table with no primary key: the first and the only
ordering column is ROW_ID which InnoDB stored to the key_ptr
buffer. */
ut_a(key_len == DATA_ROW_ID_LEN);
dfield_set_data(dfield, key_ptr, DATA_ROW_ID_LEN);
dtuple_set_n_fields(tuple, 1);
return;
}
while (key_ptr < key_end) {
ulint type = dfield_get_type(dfield)->mtype;
ut_a(field->col->mtype == type);
data_offset = 0;
is_null = FALSE;
if (!(dfield_get_type(dfield)->prtype & DATA_NOT_NULL)) {
/* The first byte in the field tells if this is
an SQL NULL value */
data_offset = 1;
if (*key_ptr != 0) {
dfield_set_null(dfield);
is_null = TRUE;
}
}
/* Calculate data length and data field total length */
if (type == DATA_BLOB) {
/* The key field is a column prefix of a BLOB or
TEXT */
ut_a(field->prefix_len > 0);
/* MySQL stores the actual data length to the first 2
bytes after the optional SQL NULL marker byte. The
storage format is little-endian, that is, the most
significant byte at a higher address. In UTF-8, MySQL
seems to reserve field->prefix_len bytes for
storing this field in the key value buffer, even
though the actual value only takes data_len bytes
from the start. */
data_len = key_ptr[data_offset]
+ 256 * key_ptr[data_offset + 1];
data_field_len = data_offset + 2 + field->prefix_len;
data_offset += 2;
/* Now that we know the length, we store the column
value like it would be a fixed char field */
} else if (field->prefix_len > 0) {
/* Looks like MySQL pads unused end bytes in the
prefix with space. Therefore, also in UTF-8, it is ok
to compare with a prefix containing full prefix_len
bytes, and no need to take at most prefix_len / 3
UTF-8 characters from the start.
If the prefix is used as the upper end of a LIKE
'abc%' query, then MySQL pads the end with chars
0xff. TODO: in that case does it any harm to compare
with the full prefix_len bytes. How do characters
0xff in UTF-8 behave? */
data_len = field->prefix_len;
data_field_len = data_offset + data_len;
} else {
data_len = dfield_get_type(dfield)->len;
data_field_len = data_offset + data_len;
}
if (UNIV_UNLIKELY
(dtype_get_mysql_type(dfield_get_type(dfield))
== DATA_MYSQL_TRUE_VARCHAR)
&& UNIV_LIKELY(type != DATA_INT)) {
/* In a MySQL key value format, a true VARCHAR is
always preceded by 2 bytes of a length field.
dfield_get_type(dfield)->len returns the maximum
'payload' len in bytes. That does not include the
2 bytes that tell the actual data length.
We added the check != DATA_INT to make sure we do
not treat MySQL ENUM or SET as a true VARCHAR! */
data_len += 2;
data_field_len += 2;
}
/* Storing may use at most data_len bytes of buf */
if (UNIV_LIKELY(!is_null)) {
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buf = row_mysql_store_col_in_innobase_format(
dfield, buf,
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/* MySQL key value format col */
FALSE,
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key_ptr + data_offset, data_len,
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dict_table_is_comp(index->table),
false, 0, 0 ,0);
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ut_a(buf <= original_buf + buf_len);
}
key_ptr += data_field_len;
if (UNIV_UNLIKELY(key_ptr > key_end)) {
/* The last field in key was not a complete key field
but a prefix of it.
Print a warning about this! HA_READ_PREFIX_LAST does
not currently work in InnoDB with partial-field key
value prefixes. Since MySQL currently uses a padding
trick to calculate LIKE 'abc%' type queries there
should never be partial-field prefixes in searches. */
ut_print_timestamp(stderr);
fputs(" InnoDB: Warning: using a partial-field"
" key prefix in search.\n"
"InnoDB: ", stderr);
dict_index_name_print(stderr, trx, index);
fprintf(stderr, ". Last data field length %lu bytes,\n"
"InnoDB: key ptr now exceeds"
" key end by %lu bytes.\n"
"InnoDB: Key value in the MySQL format:\n",
(ulong) data_field_len,
(ulong) (key_ptr - key_end));
fflush(stderr);
ut_print_buf(stderr, original_key_ptr, key_len);
2008-12-03 06:06:00 +01:00
putc('\n', stderr);
if (!is_null) {
ulint len = dfield_get_len(dfield);
dfield_set_len(dfield, len
- (ulint) (key_ptr - key_end));
}
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ut_ad(0);
}
n_fields++;
field++;
dfield++;
}
ut_a(buf <= original_buf + buf_len);
/* We set the length of tuple to n_fields: we assume that the memory
area allocated for it is big enough (usually bigger than n_fields). */
dtuple_set_n_fields(tuple, n_fields);
}
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/**************************************************************//**
Stores the row id to the prebuilt struct. */
static
void
row_sel_store_row_id_to_prebuilt(
/*=============================*/
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row_prebuilt_t* prebuilt, /*!< in/out: prebuilt */
const rec_t* index_rec, /*!< in: record */
const dict_index_t* index, /*!< in: index of the record */
const ulint* offsets) /*!< in: rec_get_offsets
(index_rec, index) */
{
const byte* data;
ulint len;
ut_ad(rec_offs_validate(index_rec, index, offsets));
data = rec_get_nth_field(
index_rec, offsets,
dict_index_get_sys_col_pos(index, DATA_ROW_ID), &len);
if (UNIV_UNLIKELY(len != DATA_ROW_ID_LEN)) {
fprintf(stderr,
"InnoDB: Error: Row id field is"
" wrong length %lu in ", (ulong) len);
dict_index_name_print(stderr, prebuilt->trx, index);
fprintf(stderr, "\n"
"InnoDB: Field number %lu, record:\n",
(ulong) dict_index_get_sys_col_pos(index,
DATA_ROW_ID));
rec_print_new(stderr, index_rec, offsets);
putc('\n', stderr);
ut_error;
}
ut_memcpy(prebuilt->row_id, data, len);
}
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#ifdef UNIV_DEBUG
/** Convert a non-SQL-NULL field from Innobase format to MySQL format. */
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# define row_sel_field_store_in_mysql_format( \
dest,templ,idx,field,src,len,prebuilt) \
row_sel_field_store_in_mysql_format_func \
(dest,templ,idx,field,src,len, prebuilt)
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#else /* UNIV_DEBUG */
/** Convert a non-SQL-NULL field from Innobase format to MySQL format. */
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# define row_sel_field_store_in_mysql_format( \
dest,templ,idx,field,src,len,prebuilt) \
row_sel_field_store_in_mysql_format_func \
(dest,templ,src,len, prebuilt)
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#endif /* UNIV_DEBUG */
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/**************************************************************//**
Stores a non-SQL-NULL field in the MySQL format. The counterpart of this
2013-12-16 15:38:05 +01:00
function is row_mysql_store_col_in_innobase_format() in row0mysql.cc. */
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static MY_ATTRIBUTE((nonnull))
void
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row_sel_field_store_in_mysql_format_func(
/*=====================================*/
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byte* dest, /*!< in/out: buffer where to store; NOTE
that BLOBs are not in themselves
stored here: the caller must allocate
and copy the BLOB into buffer before,
and pass the pointer to the BLOB in
'data' */
const mysql_row_templ_t* templ,
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/*!< in: MySQL column template.
Its following fields are referenced:
type, is_unsigned, mysql_col_len,
mbminlen, mbmaxlen */
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#ifdef UNIV_DEBUG
const dict_index_t* index,
/*!< in: InnoDB index */
ulint field_no,
/*!< in: templ->rec_field_no or
templ->clust_rec_field_no or
templ->icp_rec_field_no */
#endif /* UNIV_DEBUG */
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const byte* data, /*!< in: data to store */
2016-10-25 17:01:37 +02:00
ulint len, /*!< in: length of the data */
row_prebuilt_t* prebuilt)
/*!< in: use prebuilt->compress_heap
only here */
{
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byte* ptr;
#ifdef UNIV_DEBUG
const dict_field_t* field
= dict_index_get_nth_field(index, field_no);
#endif /* UNIV_DEBUG */
ut_ad(len != UNIV_SQL_NULL);
UNIV_MEM_ASSERT_RW(data, len);
UNIV_MEM_ASSERT_W(dest, templ->mysql_col_len);
UNIV_MEM_INVALID(dest, templ->mysql_col_len);
switch (templ->type) {
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const byte* field_end;
byte* pad;
case DATA_INT:
/* Convert integer data from Innobase to a little-endian
format, sign bit restored to normal */
ptr = dest + len;
for (;;) {
ptr--;
*ptr = *data;
if (ptr == dest) {
break;
}
data++;
}
if (!templ->is_unsigned) {
dest[len - 1] = (byte) (dest[len - 1] ^ 128);
}
ut_ad(templ->mysql_col_len == len);
break;
case DATA_VARCHAR:
case DATA_VARMYSQL:
case DATA_BINARY:
field_end = dest + templ->mysql_col_len;
if (templ->mysql_type == DATA_MYSQL_TRUE_VARCHAR) {
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/* If this is a compressed column,
decompress it first */
if (templ->compressed)
data = row_decompress_column(data, &len,
reinterpret_cast<const byte*>(
templ->zip_dict_data.str),
templ->zip_dict_data.length,
prebuilt);
/* This is a >= 5.0.3 type true VARCHAR. Store the
length of the data to the first byte or the first
two bytes of dest. */
dest = row_mysql_store_true_var_len(
dest, len, templ->mysql_length_bytes);
/* Copy the actual data. Leave the rest of the
buffer uninitialized. */
memcpy(dest, data, len);
break;
}
/* Copy the actual data */
ut_memcpy(dest, data, len);
/* Pad with trailing spaces. */
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pad = dest + len;
ut_ad(templ->mbminlen <= templ->mbmaxlen);
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/* We treat some Unicode charset strings specially. */
switch (templ->mbminlen) {
case 4:
/* InnoDB should never have stripped partial
UTF-32 characters. */
ut_a(!(len & 3));
break;
case 2:
/* A space char is two bytes,
0x0020 in UCS2 and UTF-16 */
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if (UNIV_UNLIKELY(len & 1)) {
/* A 0x20 has been stripped from the column.
Pad it back. */
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if (pad < field_end) {
*pad++ = 0x20;
}
}
}
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row_mysql_pad_col(templ->mbminlen, pad, field_end - pad);
break;
case DATA_BLOB:
/* Store a pointer to the BLOB buffer to dest: the BLOB was
already copied to the buffer in row_sel_store_mysql_rec */
row_mysql_store_blob_ref(dest, templ->mysql_col_len, data,
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len, templ->compressed,
reinterpret_cast<const byte*>(
templ->zip_dict_data.str),
templ->zip_dict_data.length,
prebuilt);
break;
case DATA_MYSQL:
memcpy(dest, data, len);
ut_ad(templ->mysql_col_len >= len);
ut_ad(templ->mbmaxlen >= templ->mbminlen);
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/* If field_no equals to templ->icp_rec_field_no,
we are examining a row pointed by "icp_rec_field_no".
There is possibility that icp_rec_field_no refers to
a field in a secondary index while templ->rec_field_no
points to field in a primary index. The length
should still be equal, unless the field pointed
by icp_rec_field_no has a prefix */
ut_ad(templ->mbmaxlen > templ->mbminlen
2013-12-16 15:38:05 +01:00
|| templ->mysql_col_len == len
|| (field_no == templ->icp_rec_field_no
&& field->prefix_len > 0));
/* The following assertion would fail for old tables
containing UTF-8 ENUM columns due to Bug #9526. */
ut_ad(!templ->mbmaxlen
|| !(templ->mysql_col_len % templ->mbmaxlen));
2013-12-16 15:38:05 +01:00
ut_ad(len * templ->mbmaxlen >= templ->mysql_col_len
|| (field_no == templ->icp_rec_field_no
&& field->prefix_len > 0));
ut_ad(!(field->prefix_len % templ->mbmaxlen));
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if (templ->mbminlen == 1 && templ->mbmaxlen != 1) {
/* Pad with spaces. This undoes the stripping
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done in row0mysql.cc, function
row_mysql_store_col_in_innobase_format(). */
memset(dest + len, 0x20, templ->mysql_col_len - len);
}
break;
default:
#ifdef UNIV_DEBUG
case DATA_SYS_CHILD:
case DATA_SYS:
/* These column types should never be shipped to MySQL. */
ut_ad(0);
case DATA_CHAR:
case DATA_FIXBINARY:
case DATA_FLOAT:
case DATA_DOUBLE:
case DATA_DECIMAL:
/* Above are the valid column types for MySQL data. */
#endif /* UNIV_DEBUG */
2013-12-16 15:38:05 +01:00
ut_ad(field->prefix_len
? field->prefix_len == len
: templ->mysql_col_len == len);
memcpy(dest, data, len);
}
}
2013-12-16 15:38:05 +01:00
#ifdef UNIV_DEBUG
/** Convert a field from Innobase format to MySQL format. */
# define row_sel_store_mysql_field(m,p,r,i,o,f,t) \
row_sel_store_mysql_field_func(m,p,r,i,o,f,t)
#else /* UNIV_DEBUG */
/** Convert a field from Innobase format to MySQL format. */
# define row_sel_store_mysql_field(m,p,r,i,o,f,t) \
row_sel_store_mysql_field_func(m,p,r,o,f,t)
#endif /* UNIV_DEBUG */
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/**************************************************************//**
Convert a field in the Innobase format to a field in the MySQL format. */
2016-08-10 19:24:58 +02:00
static MY_ATTRIBUTE((warn_unused_result))
ibool
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row_sel_store_mysql_field_func(
/*===========================*/
byte* mysql_rec, /*!< out: record in the
MySQL format */
row_prebuilt_t* prebuilt, /*!< in/out: prebuilt struct */
const rec_t* rec, /*!< in: InnoDB record;
must be protected by
a page latch */
2013-12-16 15:38:05 +01:00
#ifdef UNIV_DEBUG
const dict_index_t* index, /*!< in: index of rec */
#endif
const ulint* offsets, /*!< in: array returned by
rec_get_offsets() */
ulint field_no, /*!< in: templ->rec_field_no or
2013-12-16 15:38:05 +01:00
templ->clust_rec_field_no or
templ->icp_rec_field_no */
const mysql_row_templ_t*templ) /*!< in: row template */
{
const byte* data;
ulint len;
2009-03-26 07:11:11 +01:00
ut_ad(prebuilt->default_rec);
ut_ad(templ);
ut_ad(templ >= prebuilt->mysql_template);
ut_ad(templ < &prebuilt->mysql_template[prebuilt->n_template]);
ut_ad(field_no == templ->clust_rec_field_no
|| field_no == templ->rec_field_no
|| field_no == templ->icp_rec_field_no);
2013-12-16 15:38:05 +01:00
ut_ad(rec_offs_validate(rec, index, offsets));
if (UNIV_UNLIKELY(rec_offs_nth_extern(offsets, field_no))) {
mem_heap_t* heap;
/* Copy an externally stored field to a temporary heap */
ut_a(!prebuilt->trx->has_search_latch);
2013-11-07 21:44:46 +01:00
#ifdef UNIV_SYNC_DEBUG
2013-12-16 15:38:05 +01:00
ut_ad(!btr_search_own_any());
2013-11-07 21:44:46 +01:00
#endif
ut_ad(field_no == templ->clust_rec_field_no);
if (UNIV_UNLIKELY(templ->type == DATA_BLOB)) {
if (prebuilt->blob_heap == NULL) {
prebuilt->blob_heap = mem_heap_create(
UNIV_PAGE_SIZE);
}
heap = prebuilt->blob_heap;
} else {
heap = mem_heap_create(UNIV_PAGE_SIZE);
}
/* NOTE: if we are retrieving a big BLOB, we may
already run out of memory in the next call, which
causes an assert */
data = btr_rec_copy_externally_stored_field(
rec, offsets,
dict_table_zip_size(prebuilt->table),
field_no, &len, heap, NULL);
if (UNIV_UNLIKELY(!data)) {
/* The externally stored field was not written
yet. This record should only be seen by
recv_recovery_rollback_active() or any
TRX_ISO_READ_UNCOMMITTED transactions. */
if (heap != prebuilt->blob_heap) {
mem_heap_free(heap);
}
ut_a(prebuilt->trx->isolation_level
== TRX_ISO_READ_UNCOMMITTED);
return(FALSE);
}
ut_a(len != UNIV_SQL_NULL);
row_sel_field_store_in_mysql_format(
mysql_rec + templ->mysql_col_offset,
2016-10-25 17:01:37 +02:00
templ, index, field_no, data, len, prebuilt);
if (heap != prebuilt->blob_heap) {
mem_heap_free(heap);
}
} else {
/* Field is stored in the row. */
data = rec_get_nth_field(rec, offsets, field_no, &len);
if (len == UNIV_SQL_NULL) {
2009-03-26 07:11:11 +01:00
/* MySQL assumes that the field for an SQL
NULL value is set to the default value. */
ut_ad(templ->mysql_null_bit_mask);
UNIV_MEM_ASSERT_RW(prebuilt->default_rec
+ templ->mysql_col_offset,
templ->mysql_col_len);
mysql_rec[templ->mysql_null_byte_offset]
|= (byte) templ->mysql_null_bit_mask;
2009-03-26 07:11:11 +01:00
memcpy(mysql_rec + templ->mysql_col_offset,
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(const byte*) prebuilt->default_rec
+ templ->mysql_col_offset,
2009-03-26 07:11:11 +01:00
templ->mysql_col_len);
return(TRUE);
}
if (UNIV_UNLIKELY(templ->type == DATA_BLOB)) {
/* It is a BLOB field locally stored in the
InnoDB record: we MUST copy its contents to
prebuilt->blob_heap here because
row_sel_field_store_in_mysql_format() stores a
pointer to the data, and the data passed to us
will be invalid as soon as the
mini-transaction is committed and the page
latch on the clustered index page is
released. */
if (prebuilt->blob_heap == NULL) {
prebuilt->blob_heap = mem_heap_create(
UNIV_PAGE_SIZE);
}
2013-12-16 15:38:05 +01:00
data = static_cast<byte*>(
mem_heap_dup(prebuilt->blob_heap, data, len));
}
row_sel_field_store_in_mysql_format(
mysql_rec + templ->mysql_col_offset,
2016-10-25 17:01:37 +02:00
templ, index, field_no, data, len, prebuilt);
}
ut_ad(len != UNIV_SQL_NULL);
if (templ->mysql_null_bit_mask) {
/* It is a nullable column with a non-NULL
value */
mysql_rec[templ->mysql_null_byte_offset]
&= ~(byte) templ->mysql_null_bit_mask;
}
return(TRUE);
}
/**************************************************************//**
Convert a row in the Innobase format to a row in the MySQL format.
Note that the template in prebuilt may advise us to copy only a few
columns to mysql_rec, other columns are left blank. All columns may not
be needed in the query.
@return TRUE on success, FALSE if not all columns could be retrieved */
2016-08-10 19:24:58 +02:00
static MY_ATTRIBUTE((warn_unused_result))
ibool
row_sel_store_mysql_rec(
/*====================*/
byte* mysql_rec, /*!< out: row in the MySQL format */
row_prebuilt_t* prebuilt, /*!< in: prebuilt struct */
const rec_t* rec, /*!< in: Innobase record in the index
which was described in prebuilt's
template, or in the clustered index;
must be protected by a page latch */
ibool rec_clust, /*!< in: TRUE if rec is in the
clustered index instead of
prebuilt->index */
2013-12-16 15:38:05 +01:00
const dict_index_t* index, /*!< in: index of rec */
const ulint* offsets) /*!< in: array returned by
rec_get_offsets(rec) */
{
2013-12-16 15:38:05 +01:00
ulint i;
ut_ad(rec_clust || index == prebuilt->index);
ut_ad(!rec_clust || dict_index_is_clust(index));
if (UNIV_LIKELY_NULL(prebuilt->blob_heap)) {
mem_heap_free(prebuilt->blob_heap);
prebuilt->blob_heap = NULL;
}
2016-10-25 17:01:37 +02:00
if (UNIV_LIKELY_NULL(prebuilt->compress_heap))
mem_heap_empty(prebuilt->compress_heap);
for (i = 0; i < prebuilt->n_template; i++) {
const mysql_row_templ_t*templ = &prebuilt->mysql_template[i];
2013-12-16 15:38:05 +01:00
const ulint field_no
= rec_clust
? templ->clust_rec_field_no
: templ->rec_field_no;
/* We should never deliver column prefixes to MySQL,
except for evaluating innobase_index_cond(). */
/* ...actually, we do want to do this in order to
support the prefix query optimization.
2013-12-16 15:38:05 +01:00
ut_ad(dict_index_get_nth_field(index, field_no)->prefix_len
== 0);
...so we disable this assert. */
if (!row_sel_store_mysql_field(mysql_rec, prebuilt,
2013-12-16 15:38:05 +01:00
rec, index, offsets,
field_no, templ)) {
return(FALSE);
}
}
2013-12-16 15:38:05 +01:00
/* FIXME: We only need to read the doc_id if an FTS indexed
column is being updated.
NOTE, the record must be cluster index record. Secondary index
might not have the Doc ID */
if (dict_table_has_fts_index(prebuilt->table)
&& dict_index_is_clust(index)) {
prebuilt->fts_doc_id = fts_get_doc_id_from_rec(
prebuilt->table, rec, NULL);
}
return(TRUE);
}
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/*********************************************************************//**
Builds a previous version of a clustered index record for a consistent read
@return DB_SUCCESS or error code */
2016-08-10 19:24:58 +02:00
static MY_ATTRIBUTE((nonnull, warn_unused_result))
2013-12-16 15:38:05 +01:00
dberr_t
row_sel_build_prev_vers_for_mysql(
/*==============================*/
2009-09-07 12:22:53 +02:00
read_view_t* read_view, /*!< in: read view */
dict_index_t* clust_index, /*!< in: clustered index */
row_prebuilt_t* prebuilt, /*!< in: prebuilt struct */
const rec_t* rec, /*!< in: record in a clustered index */
ulint** offsets, /*!< in/out: offsets returned by
rec_get_offsets(rec, clust_index) */
2009-09-07 12:22:53 +02:00
mem_heap_t** offset_heap, /*!< in/out: memory heap from which
the offsets are allocated */
2009-09-07 12:22:53 +02:00
rec_t** old_vers, /*!< out: old version, or NULL if the
record does not exist in the view:
i.e., it was freshly inserted
afterwards */
2009-09-07 12:22:53 +02:00
mtr_t* mtr) /*!< in: mtr */
{
2013-12-16 15:38:05 +01:00
dberr_t err;
if (prebuilt->old_vers_heap) {
mem_heap_empty(prebuilt->old_vers_heap);
} else {
prebuilt->old_vers_heap = mem_heap_create(200);
}
err = row_vers_build_for_consistent_read(
rec, mtr, clust_index, offsets, read_view, offset_heap,
prebuilt->old_vers_heap, old_vers);
return(err);
}
2009-09-07 12:22:53 +02:00
/*********************************************************************//**
Retrieves the clustered index record corresponding to a record in a
non-clustered index. Does the necessary locking. Used in the MySQL
2009-09-07 12:22:53 +02:00
interface.
@return DB_SUCCESS, DB_SUCCESS_LOCKED_REC, or error code */
2016-08-10 19:24:58 +02:00
static MY_ATTRIBUTE((nonnull, warn_unused_result))
2013-12-16 15:38:05 +01:00
dberr_t
row_sel_get_clust_rec_for_mysql(
/*============================*/
2009-09-07 12:22:53 +02:00
row_prebuilt_t* prebuilt,/*!< in: prebuilt struct in the handle */
dict_index_t* sec_index,/*!< in: secondary index where rec resides */
const rec_t* rec, /*!< in: record in a non-clustered index; if
this is a locking read, then rec is not
allowed to be delete-marked, and that would
not make sense either */
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que_thr_t* thr, /*!< in: query thread */
const rec_t** out_rec,/*!< out: clustered record or an old version of
it, NULL if the old version did not exist
in the read view, i.e., it was a fresh
inserted version */
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ulint** offsets,/*!< in: offsets returned by
rec_get_offsets(rec, sec_index);
out: offsets returned by
rec_get_offsets(out_rec, clust_index) */
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mem_heap_t** offset_heap,/*!< in/out: memory heap from which
the offsets are allocated */
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mtr_t* mtr) /*!< in: mtr used to get access to the
non-clustered record; the same mtr is used to
access the clustered index */
{
dict_index_t* clust_index;
const rec_t* clust_rec;
rec_t* old_vers;
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dberr_t err;
trx_t* trx;
srv_stats.n_sec_rec_cluster_reads.inc();
*out_rec = NULL;
trx = thr_get_trx(thr);
row_build_row_ref_in_tuple(prebuilt->clust_ref, rec,
sec_index, *offsets, trx);
clust_index = dict_table_get_first_index(sec_index->table);
btr_pcur_open_with_no_init(clust_index, prebuilt->clust_ref,
PAGE_CUR_LE, BTR_SEARCH_LEAF,
&prebuilt->clust_pcur, 0, mtr);
clust_rec = btr_pcur_get_rec(&prebuilt->clust_pcur);
prebuilt->clust_pcur.trx_if_known = trx;
/* Note: only if the search ends up on a non-infimum record is the
low_match value the real match to the search tuple */
if (!page_rec_is_user_rec(clust_rec)
|| btr_pcur_get_low_match(&prebuilt->clust_pcur)
< dict_index_get_n_unique(clust_index)) {
/* In a rare case it is possible that no clust rec is found
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for a delete-marked secondary index record: if in row0umod.cc
in row_undo_mod_remove_clust_low() we have already removed
the clust rec, while purge is still cleaning and removing
secondary index records associated with earlier versions of
the clustered index record. In that case we know that the
clustered index record did not exist in the read view of
trx. */
if (!rec_get_deleted_flag(rec,
dict_table_is_comp(sec_index->table))
|| prebuilt->select_lock_type != LOCK_NONE) {
ut_print_timestamp(stderr);
fputs(" InnoDB: error clustered record"
" for sec rec not found\n"
"InnoDB: ", stderr);
dict_index_name_print(stderr, trx, sec_index);
fputs("\n"
"InnoDB: sec index record ", stderr);
rec_print(stderr, rec, sec_index);
fputs("\n"
"InnoDB: clust index record ", stderr);
rec_print(stderr, clust_rec, clust_index);
putc('\n', stderr);
trx_print(stderr, trx, 600);
fputs("\n"
"InnoDB: Submit a detailed bug report"
" to http://bugs.mysql.com\n", stderr);
ut_ad(0);
}
clust_rec = NULL;
err = DB_SUCCESS;
goto func_exit;
}
*offsets = rec_get_offsets(clust_rec, clust_index, *offsets,
ULINT_UNDEFINED, offset_heap);
if (prebuilt->select_lock_type != LOCK_NONE) {
/* Try to place a lock on the index record; we are searching
the clust rec with a unique condition, hence
we set a LOCK_REC_NOT_GAP type lock */
err = lock_clust_rec_read_check_and_lock(
0, btr_pcur_get_block(&prebuilt->clust_pcur),
clust_rec, clust_index, *offsets,
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static_cast<enum lock_mode>(prebuilt->select_lock_type),
LOCK_REC_NOT_GAP,
thr);
switch (err) {
case DB_SUCCESS:
case DB_SUCCESS_LOCKED_REC:
break;
default:
goto err_exit;
}
} else {
/* This is a non-locking consistent read: if necessary, fetch
a previous version of the record */
old_vers = NULL;
/* If the isolation level allows reading of uncommitted data,
then we never look for an earlier version */
if (trx->isolation_level > TRX_ISO_READ_UNCOMMITTED
&& !lock_clust_rec_cons_read_sees(
clust_rec, clust_index, *offsets,
trx->read_view)) {
/* The following call returns 'offsets' associated with
'old_vers' */
err = row_sel_build_prev_vers_for_mysql(
trx->read_view, clust_index, prebuilt,
clust_rec, offsets, offset_heap, &old_vers,
mtr);
if (err != DB_SUCCESS || old_vers == NULL) {
goto err_exit;
}
clust_rec = old_vers;
}
/* If we had to go to an earlier version of row or the
secondary index record is delete marked, then it may be that
the secondary index record corresponding to clust_rec
(or old_vers) is not rec; in that case we must ignore
such row because in our snapshot rec would not have existed.
Remember that from rec we cannot see directly which transaction
id corresponds to it: we have to go to the clustered index
record. A query where we want to fetch all rows where
the secondary index value is in some interval would return
a wrong result if we would not drop rows which we come to
visit through secondary index records that would not really
exist in our snapshot. */
if (clust_rec
&& (old_vers
|| trx->isolation_level <= TRX_ISO_READ_UNCOMMITTED
|| rec_get_deleted_flag(rec, dict_table_is_comp(
sec_index->table)))
&& !row_sel_sec_rec_is_for_clust_rec(
rec, sec_index, clust_rec, clust_index)) {
clust_rec = NULL;
#ifdef UNIV_SEARCH_DEBUG
} else {
ut_a(clust_rec == NULL
|| row_sel_sec_rec_is_for_clust_rec(
rec, sec_index, clust_rec, clust_index));
#endif
}
err = DB_SUCCESS;
}
func_exit:
*out_rec = clust_rec;
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/* Store the current position if select_lock_type is not
LOCK_NONE or if we are scanning using InnoDB APIs */
if (prebuilt->select_lock_type != LOCK_NONE
|| prebuilt->innodb_api) {
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/* We may use the cursor in update or in unlock_row():
store its position */
btr_pcur_store_position(&prebuilt->clust_pcur, mtr);
}
err_exit:
return(err);
}
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/********************************************************************//**
Restores cursor position after it has been stored. We have to take into
account that the record cursor was positioned on may have been deleted.
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Then we may have to move the cursor one step up or down.
@return TRUE if we may need to process the record the cursor is now
positioned on (i.e. we should not go to the next record yet) */
static
ibool
sel_restore_position_for_mysql(
/*===========================*/
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ibool* same_user_rec, /*!< out: TRUE if we were able to restore
the cursor on a user record with the
same ordering prefix in in the
B-tree index */
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ulint latch_mode, /*!< in: latch mode wished in
restoration */
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btr_pcur_t* pcur, /*!< in: cursor whose position
has been stored */
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ibool moves_up, /*!< in: TRUE if the cursor moves up
in the index */
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mtr_t* mtr) /*!< in: mtr; CAUTION: may commit
mtr temporarily! */
{
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ibool success;
success = btr_pcur_restore_position(latch_mode, pcur, mtr);
*same_user_rec = success;
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ut_ad(!success || pcur->rel_pos == BTR_PCUR_ON);
#ifdef UNIV_DEBUG
if (pcur->pos_state == BTR_PCUR_IS_POSITIONED_OPTIMISTIC) {
ut_ad(pcur->rel_pos == BTR_PCUR_BEFORE
|| pcur->rel_pos == BTR_PCUR_AFTER);
} else {
ut_ad(pcur->pos_state == BTR_PCUR_IS_POSITIONED);
ut_ad((pcur->rel_pos == BTR_PCUR_ON)
== btr_pcur_is_on_user_rec(pcur));
}
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#endif
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/* The position may need be adjusted for rel_pos and moves_up. */
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switch (pcur->rel_pos) {
case BTR_PCUR_ON:
if (!success && moves_up) {
next:
btr_pcur_move_to_next(pcur, mtr);
return(TRUE);
}
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return(!success);
case BTR_PCUR_AFTER_LAST_IN_TREE:
case BTR_PCUR_BEFORE_FIRST_IN_TREE:
return(TRUE);
case BTR_PCUR_AFTER:
/* positioned to record after pcur->old_rec. */
pcur->pos_state = BTR_PCUR_IS_POSITIONED;
prev:
if (btr_pcur_is_on_user_rec(pcur) && !moves_up) {
btr_pcur_move_to_prev(pcur, mtr);
}
return(TRUE);
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case BTR_PCUR_BEFORE:
/* For non optimistic restoration:
The position is now set to the record before pcur->old_rec.
For optimistic restoration:
The position also needs to take the previous search_mode into
consideration. */
switch (pcur->pos_state) {
case BTR_PCUR_IS_POSITIONED_OPTIMISTIC:
pcur->pos_state = BTR_PCUR_IS_POSITIONED;
if (pcur->search_mode == PAGE_CUR_GE) {
/* Positioned during Greater or Equal search
with BTR_PCUR_BEFORE. Optimistic restore to
the same record. If scanning for lower then
we must move to previous record.
This can happen with:
HANDLER READ idx a = (const);
HANDLER READ idx PREV; */
goto prev;
}
return(TRUE);
case BTR_PCUR_IS_POSITIONED:
if (moves_up && btr_pcur_is_on_user_rec(pcur)) {
goto next;
}
return(TRUE);
case BTR_PCUR_WAS_POSITIONED:
case BTR_PCUR_NOT_POSITIONED:
break;
}
}
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ut_ad(0);
return(TRUE);
}
/********************************************************************//**
Copies a cached field for MySQL from the fetch cache. */
static
void
row_sel_copy_cached_field_for_mysql(
/*================================*/
byte* buf, /*!< in/out: row buffer */
const byte* cache, /*!< in: cached row */
const mysql_row_templ_t*templ) /*!< in: column template */
{
ulint len;
buf += templ->mysql_col_offset;
cache += templ->mysql_col_offset;
UNIV_MEM_ASSERT_W(buf, templ->mysql_col_len);
if (templ->mysql_type == DATA_MYSQL_TRUE_VARCHAR
&& templ->type != DATA_INT) {
/* Check for != DATA_INT to make sure we do
not treat MySQL ENUM or SET as a true VARCHAR!
Find the actual length of the true VARCHAR field. */
row_mysql_read_true_varchar(
&len, cache, templ->mysql_length_bytes);
len += templ->mysql_length_bytes;
UNIV_MEM_INVALID(buf, templ->mysql_col_len);
} else {
len = templ->mysql_col_len;
}
ut_memcpy(buf, cache, len);
}
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/********************************************************************//**
Pops a cached row for MySQL from the fetch cache. */
UNIV_INLINE
void
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row_sel_dequeue_cached_row_for_mysql(
/*=================================*/
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byte* buf, /*!< in/out: buffer where to copy the
row */
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row_prebuilt_t* prebuilt) /*!< in: prebuilt struct */
{
ulint i;
const mysql_row_templ_t*templ;
const byte* cached_rec;
ut_ad(prebuilt->n_fetch_cached > 0);
ut_ad(prebuilt->mysql_prefix_len <= prebuilt->mysql_row_len);
UNIV_MEM_ASSERT_W(buf, prebuilt->mysql_row_len);
cached_rec = prebuilt->fetch_cache[prebuilt->fetch_cache_first];
if (UNIV_UNLIKELY(prebuilt->keep_other_fields_on_keyread)) {
/* Copy cache record field by field, don't touch fields that
are not covered by current key */
for (i = 0; i < prebuilt->n_template; i++) {
templ = prebuilt->mysql_template + i;
row_sel_copy_cached_field_for_mysql(
buf, cached_rec, templ);
/* Copy NULL bit of the current field from cached_rec
to buf */
if (templ->mysql_null_bit_mask) {
buf[templ->mysql_null_byte_offset]
^= (buf[templ->mysql_null_byte_offset]
^ cached_rec[templ->mysql_null_byte_offset])
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& (byte) templ->mysql_null_bit_mask;
}
}
} else if (prebuilt->mysql_prefix_len > 63) {
/* The record is long. Copy it field by field, in case
there are some long VARCHAR column of which only a
small length is being used. */
UNIV_MEM_INVALID(buf, prebuilt->mysql_prefix_len);
/* First copy the NULL bits. */
ut_memcpy(buf, cached_rec, prebuilt->null_bitmap_len);
/* Then copy the requested fields. */
for (i = 0; i < prebuilt->n_template; i++) {
row_sel_copy_cached_field_for_mysql(
buf, cached_rec, prebuilt->mysql_template + i);
}
} else {
ut_memcpy(buf, cached_rec, prebuilt->mysql_prefix_len);
}
prebuilt->n_fetch_cached--;
prebuilt->fetch_cache_first++;
if (prebuilt->n_fetch_cached == 0) {
prebuilt->fetch_cache_first = 0;
}
}
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/********************************************************************//**
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Initialise the prefetch cache. */
UNIV_INLINE
void
row_sel_prefetch_cache_init(
/*========================*/
row_prebuilt_t* prebuilt) /*!< in/out: prebuilt struct */
{
ulint i;
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ulint sz;
byte* ptr;
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/* Reserve space for the magic number. */
sz = UT_ARR_SIZE(prebuilt->fetch_cache) * (prebuilt->mysql_row_len + 8);
ptr = static_cast<byte*>(mem_alloc(sz));
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for (i = 0; i < UT_ARR_SIZE(prebuilt->fetch_cache); i++) {
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/* A user has reported memory corruption in these
buffers in Linux. Put magic numbers there to help
to track a possible bug. */
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mach_write_to_4(ptr, ROW_PREBUILT_FETCH_MAGIC_N);
ptr += 4;
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prebuilt->fetch_cache[i] = ptr;
ptr += prebuilt->mysql_row_len;
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mach_write_to_4(ptr, ROW_PREBUILT_FETCH_MAGIC_N);
ptr += 4;
}
}
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/********************************************************************//**
Get the last fetch cache buffer from the queue.
@return pointer to buffer. */
UNIV_INLINE
byte*
row_sel_fetch_last_buf(
/*===================*/
row_prebuilt_t* prebuilt) /*!< in/out: prebuilt struct */
{
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ut_ad(!prebuilt->templ_contains_blob);
ut_ad(prebuilt->n_fetch_cached < MYSQL_FETCH_CACHE_SIZE);
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if (prebuilt->fetch_cache[0] == NULL) {
/* Allocate memory for the fetch cache */
ut_ad(prebuilt->n_fetch_cached == 0);
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row_sel_prefetch_cache_init(prebuilt);
}
ut_ad(prebuilt->fetch_cache_first == 0);
UNIV_MEM_INVALID(prebuilt->fetch_cache[prebuilt->n_fetch_cached],
prebuilt->mysql_row_len);
return(prebuilt->fetch_cache[prebuilt->n_fetch_cached]);
}
/********************************************************************//**
Pushes a row for MySQL to the fetch cache. */
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UNIV_INLINE
void
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row_sel_enqueue_cache_row_for_mysql(
/*================================*/
byte* mysql_rec, /*!< in/out: MySQL record */
row_prebuilt_t* prebuilt) /*!< in/out: prebuilt struct */
{
/* For non ICP code path the row should already exist in the
next fetch cache slot. */
if (prebuilt->idx_cond != NULL) {
byte* dest = row_sel_fetch_last_buf(prebuilt);
ut_memcpy(dest, mysql_rec, prebuilt->mysql_row_len);
}
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++prebuilt->n_fetch_cached;
}
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/*********************************************************************//**
Tries to do a shortcut to fetch a clustered index record with a unique key,
using the hash index if possible (not always). We assume that the search
mode is PAGE_CUR_GE, it is a consistent read, there is a read view in trx,
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btr search latch has been locked in S-mode if AHI is enabled.
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@return SEL_FOUND, SEL_EXHAUSTED, SEL_RETRY */
static
ulint
row_sel_try_search_shortcut_for_mysql(
/*==================================*/
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const rec_t** out_rec,/*!< out: record if found */
row_prebuilt_t* prebuilt,/*!< in: prebuilt struct */
ulint** offsets,/*!< in/out: for rec_get_offsets(*out_rec) */
mem_heap_t** heap, /*!< in/out: heap for rec_get_offsets() */
mtr_t* mtr) /*!< in: started mtr */
{
dict_index_t* index = prebuilt->index;
const dtuple_t* search_tuple = prebuilt->search_tuple;
btr_pcur_t* pcur = &prebuilt->pcur;
trx_t* trx = prebuilt->trx;
const rec_t* rec;
ut_ad(dict_index_is_clust(index));
ut_ad(!prebuilt->templ_contains_blob);
#ifndef UNIV_SEARCH_DEBUG
2013-11-07 21:44:46 +01:00
ut_ad(trx->has_search_latch);
btr_pcur_open_with_no_init(index, search_tuple, PAGE_CUR_GE,
BTR_SEARCH_LEAF, pcur,
RW_S_LATCH,
mtr);
#else /* UNIV_SEARCH_DEBUG */
btr_pcur_open_with_no_init(index, search_tuple, PAGE_CUR_GE,
BTR_SEARCH_LEAF, pcur,
0,
mtr);
#endif /* UNIV_SEARCH_DEBUG */
rec = btr_pcur_get_rec(pcur);
if (!page_rec_is_user_rec(rec)) {
return(SEL_RETRY);
}
/* As the cursor is now placed on a user record after a search with
the mode PAGE_CUR_GE, the up_match field in the cursor tells how many
fields in the user record matched to the search tuple */
if (btr_pcur_get_up_match(pcur) < dtuple_get_n_fields(search_tuple)) {
return(SEL_EXHAUSTED);
}
/* This is a non-locking consistent read: if necessary, fetch
a previous version of the record */
*offsets = rec_get_offsets(rec, index, *offsets,
ULINT_UNDEFINED, heap);
if (!lock_clust_rec_cons_read_sees(rec, index,
*offsets, trx->read_view)) {
return(SEL_RETRY);
}
if (rec_get_deleted_flag(rec, dict_table_is_comp(index->table))) {
return(SEL_EXHAUSTED);
}
*out_rec = rec;
return(SEL_FOUND);
}
/*********************************************************************//**
Check a pushed-down index condition.
@return ICP_NO_MATCH, ICP_MATCH, or ICP_OUT_OF_RANGE */
static
enum icp_result
row_search_idx_cond_check(
/*======================*/
byte* mysql_rec, /*!< out: record
in MySQL format (invalid unless
prebuilt->idx_cond!=NULL and
we return ICP_MATCH) */
row_prebuilt_t* prebuilt, /*!< in/out: prebuilt struct
for the table handle */
const rec_t* rec, /*!< in: InnoDB record */
const ulint* offsets) /*!< in: rec_get_offsets() */
{
enum icp_result result;
ulint i;
ut_ad(rec_offs_validate(rec, prebuilt->index, offsets));
if (!prebuilt->idx_cond) {
return(ICP_MATCH);
}
2013-12-16 15:38:05 +01:00
MONITOR_INC(MONITOR_ICP_ATTEMPTS);
/* Convert to MySQL format those fields that are needed for
evaluating the index condition. */
if (UNIV_LIKELY_NULL(prebuilt->blob_heap)) {
mem_heap_empty(prebuilt->blob_heap);
}
for (i = 0; i < prebuilt->idx_cond_n_cols; i++) {
const mysql_row_templ_t*templ = &prebuilt->mysql_template[i];
if (!row_sel_store_mysql_field(mysql_rec, prebuilt,
2013-12-16 15:38:05 +01:00
rec, prebuilt->index, offsets,
templ->icp_rec_field_no,
templ)) {
return(ICP_NO_MATCH);
}
}
/* We assume that the index conditions on
case-insensitive columns are case-insensitive. The
case of such columns may be wrong in a secondary
index, if the case of the column has been updated in
the past, or a record has been deleted and a record
inserted in a different case. */
2013-12-16 15:38:05 +01:00
result = innobase_index_cond(prebuilt->idx_cond);
switch (result) {
case ICP_MATCH:
/* Convert the remaining fields to MySQL format.
If this is a secondary index record, we must defer
this until we have fetched the clustered index record. */
if (!prebuilt->need_to_access_clustered
|| dict_index_is_clust(prebuilt->index)) {
2013-12-16 15:38:05 +01:00
if (!row_sel_store_mysql_rec(
mysql_rec, prebuilt, rec, FALSE,
prebuilt->index, offsets)) {
ut_ad(dict_index_is_clust(prebuilt->index));
2013-12-16 15:38:05 +01:00
return(ICP_NO_MATCH);
}
}
2013-12-16 15:38:05 +01:00
MONITOR_INC(MONITOR_ICP_MATCH);
return(result);
case ICP_NO_MATCH:
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MONITOR_INC(MONITOR_ICP_NO_MATCH);
return(result);
case ICP_OUT_OF_RANGE:
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MONITOR_INC(MONITOR_ICP_OUT_OF_RANGE);
return(result);
case ICP_ERROR:
case ICP_ABORTED_BY_USER:
return(result);
}
ut_error;
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return(result);
}
2009-09-07 12:22:53 +02:00
/********************************************************************//**
Searches for rows in the database. This is used in the interface to
MySQL. This function opens a cursor, and also implements fetch next
and fetch prev. NOTE that if we do a search with a full key value
from a unique index (ROW_SEL_EXACT), then we will not store the cursor
2009-09-07 12:22:53 +02:00
position and fetch next or fetch prev must not be tried to the cursor!
@return DB_SUCCESS, DB_RECORD_NOT_FOUND, DB_END_OF_INDEX, DB_DEADLOCK,
Fix for lp:711565 "Index Condition Pushdown can make a thread hold MyISAM locks as well as be unKILLable for long time" - In Maria/MyISAM: Release/re-acquire locks to give queries that wait on them a chance to make progress - In Maria/MyISAM: Change from numeric constants to ICP_RES values. - In Maria: Do check index condition in maria_rprev() (was lost in the merge/backport?) - In Maria/MyISAM/XtraDB: Check if the query was killed, and return immediately if it was. Added new storage engine error: HA_ERR_ABORTED_BY_USER, for handler to signal that it detected a kill of the query and aborted Authors: Sergey Petrunia & Monty include/my_base.h: Added HA_ERR_ABORTED_BY_USER, for handler to signal that it detected a kill of the query and aborted include/my_handler.h: Added comment mysql-test/r/myisam_icp.result: Updated test mysql-test/t/myisam_icp.test: Drop used tables at start of test Added test case that can help with manual testing of killing index condition pushdown query. mysys/my_handler_errors.h: Text for new storage engine error sql/handler.cc: If engine got HA_ERR_ABORTED_BY_USER, send kill message. sql/multi_range_read.cc: Return error code storage/maria/ha_maria.cc: Added ma_killed_in_mariadb() to detect kill. Ensure that file->external_ref points to TABLE object. storage/maria/ma_extra.c: Dummy test-if-killed for standalone storage/maria/ma_key.c: If ma_check_index_cond() fails, set my_errno and info->cur_row.lastpos storage/maria/ma_rkey.c: Release/re-acquire locks to give queries that wait on them a chance to make progress Check if the query was killed, and return immediately if it was storage/maria/ma_rnext.c: Check if the query was killed, and return immediately if it was Added missing fast_ma_writeinfo(info) storage/maria/ma_rnext_same.c: Check if the query was killed, and return immediately if it was Added missing fast_ma_writeinfo(info) storage/maria/ma_rprev.c: Check if the query was killed, and return immediately if it was Added missing fast_ma_writeinfo(info) and ma_check_index_cond() storage/maria/ma_search.c: Give error message if we find a wrong key storage/maria/ma_static.c: Added pointer to test-if-killed function storage/maria/maria_def.h: New prototypes storage/myisam/ha_myisam.cc: Added mi_killed_in_mariadb() Ensure that file->external_ref points to TABLE object. storage/myisam/mi_extra.c: Dummy test-if-killed for standalone storage/myisam/mi_key.c: If ma_check_index_cond() fails, set my_errno and info->lastpos storage/myisam/mi_rkey.c: Ensure that info->lastpos= HA_OFFSET_ERROR in case of error Release/re-acquire locks to give queries that wait on them a chance to make progress Check if the query was killed, and return immediately if it was Reorder code to do less things in case of error. Added missing fast_mi_writeinfo() storage/myisam/mi_rnext.c: Check if the query was killed, and return immediately if it was Simplify old ICP code Added missing fast_ma_writeinfo(info) storage/myisam/mi_rnext_same.c: Check if the query was killed, and return immediately if it was Added missing fast_mi_writeinfo(info) storage/myisam/mi_rprev.c: Check if the query was killed, and return immediately if it was Simplify error handling of ICP Added missing fast_mi_writeinfo(info) storage/myisam/mi_search.c: Give error message if we find a wrong key storage/myisam/mi_static.c: Added pointer to test-if-killed function storage/myisam/myisamdef.h: New prototypes storage/xtradb/handler/ha_innodb.cc: Added DB_SEARCH_ABORTED_BY_USER and ha_innobase::is_thd_killed() Check if the query was killed, and return immediately if it was storage/xtradb/handler/ha_innodb.h: Added prototype storage/xtradb/include/db0err.h: Added DB_SEARCH_ABORTED_BY_USER storage/xtradb/include/row0mysql.h: Added possible ICP errors storage/xtradb/row/row0sel.c: Use ICP errors instead of constants. Detect if killed and return B_SEARCH_ABORTED_BY_USER
2011-02-18 16:43:59 +01:00
DB_LOCK_TABLE_FULL, DB_CORRUPTION, DB_SEARCH_ABORTED_BY_USER or
DB_TOO_BIG_RECORD */
UNIV_INTERN
2013-12-16 15:38:05 +01:00
dberr_t
row_search_for_mysql(
/*=================*/
2009-09-07 12:22:53 +02:00
byte* buf, /*!< in/out: buffer for the fetched
row in the MySQL format */
2009-09-07 12:22:53 +02:00
ulint mode, /*!< in: search mode PAGE_CUR_L, ... */
row_prebuilt_t* prebuilt, /*!< in: prebuilt struct for the
table handle; this contains the info
of search_tuple, index; if search
tuple contains 0 fields then we
position the cursor at the start or
the end of the index, depending on
'mode' */
2009-09-07 12:22:53 +02:00
ulint match_mode, /*!< in: 0 or ROW_SEL_EXACT or
ROW_SEL_EXACT_PREFIX */
2009-09-07 12:22:53 +02:00
ulint direction) /*!< in: 0 or ROW_SEL_NEXT or
ROW_SEL_PREV; NOTE: if this is != 0,
then prebuilt must have a pcur
with stored position! In opening of a
cursor 'direction' should be 0. */
{
dict_index_t* index = prebuilt->index;
ibool comp = dict_table_is_comp(index->table);
const dtuple_t* search_tuple = prebuilt->search_tuple;
btr_pcur_t* pcur = &prebuilt->pcur;
trx_t* trx = prebuilt->trx;
dict_index_t* clust_index;
que_thr_t* thr;
const rec_t* rec;
2013-12-16 15:38:05 +01:00
const rec_t* result_rec = NULL;
const rec_t* clust_rec;
2013-12-16 15:38:05 +01:00
dberr_t err = DB_SUCCESS;
ibool unique_search = FALSE;
ibool mtr_has_extra_clust_latch = FALSE;
ibool moves_up = FALSE;
ibool set_also_gap_locks = TRUE;
/* if the query is a plain locking SELECT, and the isolation level
is <= TRX_ISO_READ_COMMITTED, then this is set to FALSE */
ibool did_semi_consistent_read = FALSE;
/* if the returned record was locked and we did a semi-consistent
read (fetch the newest committed version), then this is set to
TRUE */
#ifdef UNIV_SEARCH_DEBUG
ulint cnt = 0;
#endif /* UNIV_SEARCH_DEBUG */
ulint next_offs;
ibool same_user_rec;
mtr_t mtr;
mem_heap_t* heap = NULL;
ulint offsets_[REC_OFFS_NORMAL_SIZE];
ulint* offsets = offsets_;
ibool table_lock_waited = FALSE;
2013-12-16 15:38:05 +01:00
byte* next_buf = 0;
ibool use_clustered_index = FALSE;
rec_offs_init(offsets_);
ut_ad(index && pcur && search_tuple);
2013-12-16 15:38:05 +01:00
/* We don't support FTS queries from the HANDLER interfaces, because
we implemented FTS as reversed inverted index with auxiliary tables.
So anything related to traditional index query would not apply to
it. */
if (index->type & DICT_FTS) {
return(DB_END_OF_INDEX);
}
2013-11-07 21:44:46 +01:00
ut_ad(!trx->has_search_latch);
#ifdef UNIV_SYNC_DEBUG
ut_ad(!btr_search_own_any());
ut_ad(!sync_thread_levels_nonempty_trx(trx->has_search_latch));
#endif /* UNIV_SYNC_DEBUG */
2013-12-16 15:38:05 +01:00
if (dict_table_is_discarded(prebuilt->table)) {
2013-12-16 15:38:05 +01:00
return(DB_TABLESPACE_DELETED);
} else if (prebuilt->table->ibd_file_missing) {
2013-12-16 15:38:05 +01:00
return(DB_TABLESPACE_NOT_FOUND);
} else if (prebuilt->table->is_encrypted) {
return(DB_DECRYPTION_FAILED);
2013-12-16 15:38:05 +01:00
} else if (!prebuilt->index_usable) {
2009-09-07 12:22:53 +02:00
return(DB_MISSING_HISTORY);
2013-12-16 15:38:05 +01:00
} else if (dict_index_is_corrupted(index)) {
return(DB_CORRUPTION);
2013-12-16 15:38:05 +01:00
} else if (prebuilt->magic_n != ROW_PREBUILT_ALLOCATED) {
fprintf(stderr,
"InnoDB: Error: trying to free a corrupt\n"
"InnoDB: table handle. Magic n %lu, table name ",
(ulong) prebuilt->magic_n);
ut_print_name(stderr, trx, TRUE, prebuilt->table->name);
putc('\n', stderr);
mem_analyze_corruption(prebuilt);
ut_error;
}
#if 0
/* August 19, 2005 by Heikki: temporarily disable this error
print until the cursor lock count is done correctly.
See bugs #12263 and #12456!*/
if (trx->n_mysql_tables_in_use == 0
&& UNIV_UNLIKELY(prebuilt->select_lock_type == LOCK_NONE)) {
/* Note that if MySQL uses an InnoDB temp table that it
created inside LOCK TABLES, then n_mysql_tables_in_use can
be zero; in that case select_lock_type is set to LOCK_X in
::start_stmt. */
fputs("InnoDB: Error: MySQL is trying to perform a SELECT\n"
"InnoDB: but it has not locked"
" any tables in ::external_lock()!\n",
stderr);
trx_print(stderr, trx, 600);
fputc('\n', stderr);
}
#endif
#if 0
fprintf(stderr, "Match mode %lu\n search tuple ",
(ulong) match_mode);
dtuple_print(search_tuple);
fprintf(stderr, "N tables locked %lu\n",
(ulong) trx->mysql_n_tables_locked);
#endif
/* Reset the new record lock info if srv_locks_unsafe_for_binlog
is set or session is using a READ COMMITED isolation level. Then
we are able to remove the record locks set here on an individual
row. */
2009-08-09 09:04:58 +02:00
prebuilt->new_rec_locks = 0;
/*-------------------------------------------------------------*/
/* PHASE 1: Try to pop the row from the prefetch cache */
if (UNIV_UNLIKELY(direction == 0)) {
trx->op_info = "starting index read";
prebuilt->n_rows_fetched = 0;
prebuilt->n_fetch_cached = 0;
prebuilt->fetch_cache_first = 0;
if (prebuilt->sel_graph == NULL) {
/* Build a dummy select query graph */
row_prebuild_sel_graph(prebuilt);
}
} else {
trx->op_info = "fetching rows";
if (prebuilt->n_rows_fetched == 0) {
prebuilt->fetch_direction = direction;
}
if (UNIV_UNLIKELY(direction != prebuilt->fetch_direction)) {
if (UNIV_UNLIKELY(prebuilt->n_fetch_cached > 0)) {
ut_error;
/* TODO: scrollable cursor: restore cursor to
the place of the latest returned row,
or better: prevent caching for a scroll
cursor! */
}
prebuilt->n_rows_fetched = 0;
prebuilt->n_fetch_cached = 0;
prebuilt->fetch_cache_first = 0;
} else if (UNIV_LIKELY(prebuilt->n_fetch_cached > 0)) {
2013-12-16 15:38:05 +01:00
row_sel_dequeue_cached_row_for_mysql(buf, prebuilt);
prebuilt->n_rows_fetched++;
err = DB_SUCCESS;
goto func_exit;
}
if (prebuilt->fetch_cache_first > 0
&& prebuilt->fetch_cache_first < MYSQL_FETCH_CACHE_SIZE) {
/* The previous returned row was popped from the fetch
cache, but the cache was not full at the time of the
popping: no more rows can exist in the result set */
err = DB_RECORD_NOT_FOUND;
goto func_exit;
}
prebuilt->n_rows_fetched++;
if (prebuilt->n_rows_fetched > 1000000000) {
/* Prevent wrap-over */
prebuilt->n_rows_fetched = 500000000;
}
mode = pcur->search_mode;
}
/* In a search where at most one record in the index may match, we
can use a LOCK_REC_NOT_GAP type record lock when locking a
non-delete-marked matching record.
Note that in a unique secondary index there may be different
delete-marked versions of a record where only the primary key
values differ: thus in a secondary index we must use next-key
locks when locking delete-marked records. */
if (match_mode == ROW_SEL_EXACT
&& dict_index_is_unique(index)
&& dtuple_get_n_fields(search_tuple)
== dict_index_get_n_unique(index)
&& (dict_index_is_clust(index)
|| !dtuple_contains_null(search_tuple))) {
/* Note above that a UNIQUE secondary index can contain many
rows with the same key value if one of the columns is the SQL
null. A clustered index under MySQL can never contain null
columns because we demand that all the columns in primary key
are non-null. */
unique_search = TRUE;
/* Even if the condition is unique, MySQL seems to try to
retrieve also a second row if a primary key contains more than
1 column. Return immediately if this is not a HANDLER
command. */
if (UNIV_UNLIKELY(direction != 0
&& !prebuilt->used_in_HANDLER)) {
err = DB_RECORD_NOT_FOUND;
goto func_exit;
}
}
mtr_start_trx(&mtr, trx);
/*-------------------------------------------------------------*/
/* PHASE 2: Try fast adaptive hash index search if possible */
/* Next test if this is the special case where we can use the fast
adaptive hash index to try the search. Since we must release the
search system latch when we retrieve an externally stored field, we
cannot use the adaptive hash index in a search in the case the row
may be long and there may be externally stored fields */
if (UNIV_UNLIKELY(direction == 0)
&& unique_search
&& dict_index_is_clust(index)
&& !prebuilt->templ_contains_blob
&& !prebuilt->used_in_HANDLER
2013-12-16 15:38:05 +01:00
&& (prebuilt->mysql_row_len < UNIV_PAGE_SIZE / 8)
&& !prebuilt->innodb_api) {
mode = PAGE_CUR_GE;
if (trx->mysql_n_tables_locked == 0
&& prebuilt->select_lock_type == LOCK_NONE
&& trx->isolation_level > TRX_ISO_READ_UNCOMMITTED
&& trx->read_view) {
/* This is a SELECT query done as a consistent read,
and the read view has already been allocated:
let us try a search shortcut through the hash
index.
NOTE that we must also test that
mysql_n_tables_locked == 0, because this might
also be INSERT INTO ... SELECT ... or
CREATE TABLE ... SELECT ... . Our algorithm is
NOT prepared to inserts interleaved with the SELECT,
and if we try that, we can deadlock on the adaptive
hash index semaphore! */
#ifndef UNIV_SEARCH_DEBUG
2013-11-07 21:44:46 +01:00
ut_ad(!trx->has_search_latch);
rw_lock_s_lock(btr_search_get_latch(index));
trx->has_search_latch = TRUE;
#endif
switch (row_sel_try_search_shortcut_for_mysql(
&rec, prebuilt, &offsets, &heap,
&mtr)) {
case SEL_FOUND:
#ifdef UNIV_SEARCH_DEBUG
ut_a(0 == cmp_dtuple_rec(search_tuple,
rec, offsets));
#endif
/* At this point, rec is protected by
a page latch that was acquired by
row_sel_try_search_shortcut_for_mysql().
The latch will not be released until
mtr_commit(&mtr). */
ut_ad(!rec_get_deleted_flag(rec, comp));
if (prebuilt->idx_cond) {
switch (row_search_idx_cond_check(
buf, prebuilt,
rec, offsets)) {
case ICP_NO_MATCH:
case ICP_OUT_OF_RANGE:
case ICP_ABORTED_BY_USER:
case ICP_ERROR:
goto shortcut_mismatch;
case ICP_MATCH:
goto shortcut_match;
}
}
2013-12-16 15:38:05 +01:00
if (!row_sel_store_mysql_rec(
buf, prebuilt,
rec, FALSE, index, offsets)) {
/* Only fresh inserts may contain
incomplete externally stored
columns. Pretend that such
records do not exist. Such
records may only be accessed
at the READ UNCOMMITTED
isolation level or when
rolling back a recovered
transaction. Rollback happens
at a lower level, not here. */
/* Proceed as in case SEL_RETRY. */
break;
}
shortcut_match:
mtr_commit(&mtr);
/* ut_print_name(stderr, index->name);
fputs(" shortcut\n", stderr); */
err = DB_SUCCESS;
2013-11-07 21:44:46 +01:00
goto release_search_latch;
case SEL_EXHAUSTED:
shortcut_mismatch:
mtr_commit(&mtr);
/* ut_print_name(stderr, index->name);
fputs(" record not found 2\n", stderr); */
err = DB_RECORD_NOT_FOUND;
2013-11-07 21:44:46 +01:00
release_search_latch:
rw_lock_s_unlock(
btr_search_get_latch(index));
trx->has_search_latch = FALSE;
/* NOTE that we do NOT store the cursor
position */
goto func_exit;
case SEL_RETRY:
break;
default:
ut_ad(0);
}
mtr_commit(&mtr);
mtr_start(&mtr);
2013-11-07 21:44:46 +01:00
rw_lock_s_unlock(btr_search_get_latch(index));
trx->has_search_latch = FALSE;
}
}
/*-------------------------------------------------------------*/
/* PHASE 3: Open or restore index cursor position */
2013-11-07 21:44:46 +01:00
ut_ad(!trx->has_search_latch);
#ifdef UNIV_SYNC_DEBUG
ut_ad(!btr_search_own_any());
#endif
2013-12-16 15:38:05 +01:00
/* The state of a running trx can only be changed by the
thread that is currently serving the transaction. Because we
are that thread, we can read trx->state without holding any
mutex. */
ut_ad(prebuilt->sql_stat_start || trx->state == TRX_STATE_ACTIVE);
ut_ad(trx->state == TRX_STATE_NOT_STARTED
|| trx->state == TRX_STATE_ACTIVE);
ut_ad(prebuilt->sql_stat_start
|| prebuilt->select_lock_type != LOCK_NONE
|| trx->read_view);
trx_start_if_not_started(trx);
if (trx->isolation_level <= TRX_ISO_READ_COMMITTED
&& prebuilt->select_lock_type != LOCK_NONE
&& trx->mysql_thd != NULL
2008-12-03 06:06:00 +01:00
&& thd_is_select(trx->mysql_thd)) {
/* It is a plain locking SELECT and the isolation
level is low: do not lock gaps */
2008-12-03 06:06:00 +01:00
set_also_gap_locks = FALSE;
}
/* Note that if the search mode was GE or G, then the cursor
naturally moves upward (in fetch next) in alphabetical order,
otherwise downward */
if (UNIV_UNLIKELY(direction == 0)) {
if (mode == PAGE_CUR_GE || mode == PAGE_CUR_G) {
moves_up = TRUE;
}
} else if (direction == ROW_SEL_NEXT) {
moves_up = TRUE;
}
thr = que_fork_get_first_thr(prebuilt->sel_graph);
que_thr_move_to_run_state_for_mysql(thr, trx);
clust_index = dict_table_get_first_index(index->table);
/* Do some start-of-statement preparations */
if (!prebuilt->sql_stat_start) {
/* No need to set an intention lock or assign a read view */
if (UNIV_UNLIKELY
(trx->read_view == NULL
&& prebuilt->select_lock_type == LOCK_NONE)) {
fputs("InnoDB: Error: MySQL is trying to"
" perform a consistent read\n"
"InnoDB: but the read view is not assigned!\n",
stderr);
trx_print(stderr, trx, 600);
fputc('\n', stderr);
ut_error;
}
} else if (prebuilt->select_lock_type == LOCK_NONE) {
/* This is a consistent read */
/* Assign a read view for the query */
trx_assign_read_view(trx);
prebuilt->sql_stat_start = FALSE;
} else {
wait_table_again:
err = lock_table(0, index->table,
prebuilt->select_lock_type == LOCK_S
? LOCK_IS : LOCK_IX, thr);
if (err != DB_SUCCESS) {
table_lock_waited = TRUE;
goto lock_table_wait;
}
prebuilt->sql_stat_start = FALSE;
}
/* Open or restore index cursor position */
if (UNIV_LIKELY(direction != 0)) {
ibool need_to_process = sel_restore_position_for_mysql(
&same_user_rec, BTR_SEARCH_LEAF,
pcur, moves_up, &mtr);
if (UNIV_UNLIKELY(need_to_process)) {
if (UNIV_UNLIKELY(prebuilt->row_read_type
== ROW_READ_DID_SEMI_CONSISTENT)) {
/* We did a semi-consistent read,
but the record was removed in
the meantime. */
prebuilt->row_read_type
= ROW_READ_TRY_SEMI_CONSISTENT;
}
} else if (UNIV_LIKELY(prebuilt->row_read_type
!= ROW_READ_DID_SEMI_CONSISTENT)) {
/* The cursor was positioned on the record
that we returned previously. If we need
to repeat a semi-consistent read as a
pessimistic locking read, the record
cannot be skipped. */
goto next_rec;
}
} else if (dtuple_get_n_fields(search_tuple) > 0) {
err = btr_pcur_open_with_no_init(index, search_tuple, mode,
BTR_SEARCH_LEAF,
pcur, 0, &mtr);
if (err != DB_SUCCESS) {
rec = NULL;
goto lock_wait_or_error;
}
pcur->trx_if_known = trx;
rec = btr_pcur_get_rec(pcur);
if (!moves_up
&& !page_rec_is_supremum(rec)
&& set_also_gap_locks
&& !(srv_locks_unsafe_for_binlog
|| trx->isolation_level <= TRX_ISO_READ_COMMITTED)
&& prebuilt->select_lock_type != LOCK_NONE) {
/* Try to place a gap lock on the next index record
to prevent phantoms in ORDER BY ... DESC queries */
2013-12-16 15:38:05 +01:00
const rec_t* next_rec = page_rec_get_next_const(rec);
2013-12-16 15:38:05 +01:00
offsets = rec_get_offsets(next_rec, index, offsets,
ULINT_UNDEFINED, &heap);
err = sel_set_rec_lock(btr_pcur_get_block(pcur),
2013-12-16 15:38:05 +01:00
next_rec, index, offsets,
prebuilt->select_lock_type,
LOCK_GAP, thr);
switch (err) {
case DB_SUCCESS_LOCKED_REC:
err = DB_SUCCESS;
case DB_SUCCESS:
break;
default:
goto lock_wait_or_error;
}
}
2013-12-16 15:38:05 +01:00
} else if (mode == PAGE_CUR_G || mode == PAGE_CUR_L) {
err = btr_pcur_open_at_index_side(
2013-12-16 15:38:05 +01:00
mode == PAGE_CUR_G, index, BTR_SEARCH_LEAF,
pcur, false, 0, &mtr);
if (err != DB_SUCCESS) {
if (err == DB_DECRYPTION_FAILED) {
ib_push_warning(trx->mysql_thd,
DB_DECRYPTION_FAILED,
"Table %s is encrypted but encryption service or"
" used key_id is not available. "
" Can't continue reading table.",
prebuilt->table->name);
index->table->is_encrypted = true;
}
rec = NULL;
goto lock_wait_or_error;
}
}
rec_loop:
2013-07-16 14:55:47 +02:00
DEBUG_SYNC_C("row_search_rec_loop");
2013-02-28 22:23:45 +01:00
if (trx_is_interrupted(trx)) {
2013-07-16 14:55:47 +02:00
btr_pcur_store_position(pcur, &mtr);
2013-02-28 22:23:45 +01:00
err = DB_INTERRUPTED;
goto normal_return;
}
/*-------------------------------------------------------------*/
/* PHASE 4: Look for matching records in a loop */
rec = btr_pcur_get_rec(pcur);
2010-03-22 21:42:52 +01:00
if (!rec) {
err = DB_DECRYPTION_FAILED;
goto lock_wait_or_error;
}
2013-05-08 09:52:54 +02:00
SRV_CORRUPT_TABLE_CHECK(rec,
{
2010-03-22 21:42:52 +01:00
err = DB_CORRUPTION;
goto lock_wait_or_error;
2013-05-08 09:52:54 +02:00
});
2010-03-22 21:42:52 +01:00
ut_ad(!!page_rec_is_comp(rec) == comp);
#ifdef UNIV_SEARCH_DEBUG
/*
fputs("Using ", stderr);
2013-12-16 15:38:05 +01:00
dict_index_name_print(stderr, trx, index);
fprintf(stderr, " cnt %lu ; Page no %lu\n", cnt,
page_get_page_no(page_align(rec)));
2013-12-16 15:38:05 +01:00
rec_print(stderr, rec, index);
printf("delete-mark: %lu\n",
rec_get_deleted_flag(rec, page_rec_is_comp(rec)));
*/
#endif /* UNIV_SEARCH_DEBUG */
if (page_rec_is_infimum(rec)) {
/* The infimum record on a page cannot be in the result set,
and neither can a record lock be placed on it: we skip such
a record. */
goto next_rec;
}
if (page_rec_is_supremum(rec)) {
if (set_also_gap_locks
&& !(srv_locks_unsafe_for_binlog
|| trx->isolation_level <= TRX_ISO_READ_COMMITTED)
&& prebuilt->select_lock_type != LOCK_NONE) {
/* Try to place a lock on the index record */
/* If innodb_locks_unsafe_for_binlog option is used
or this session is using a READ COMMITTED or lower isolation
level we do not lock gaps. Supremum record is really
a gap and therefore we do not set locks there. */
offsets = rec_get_offsets(rec, index, offsets,
ULINT_UNDEFINED, &heap);
err = sel_set_rec_lock(btr_pcur_get_block(pcur),
rec, index, offsets,
prebuilt->select_lock_type,
LOCK_ORDINARY, thr);
switch (err) {
case DB_SUCCESS_LOCKED_REC:
err = DB_SUCCESS;
case DB_SUCCESS:
break;
default:
goto lock_wait_or_error;
}
}
/* A page supremum record cannot be in the result set: skip
it now that we have placed a possible lock on it */
goto next_rec;
}
/*-------------------------------------------------------------*/
/* Do sanity checks in case our cursor has bumped into page
corruption */
if (comp) {
next_offs = rec_get_next_offs(rec, TRUE);
if (UNIV_UNLIKELY(next_offs < PAGE_NEW_SUPREMUM)) {
goto wrong_offs;
}
} else {
next_offs = rec_get_next_offs(rec, FALSE);
if (UNIV_UNLIKELY(next_offs < PAGE_OLD_SUPREMUM)) {
goto wrong_offs;
}
}
if (UNIV_UNLIKELY(next_offs >= UNIV_PAGE_SIZE - PAGE_DIR)) {
wrong_offs:
2013-12-16 15:38:05 +01:00
if (srv_pass_corrupt_table && index->table->space != 0 &&
index->table->space < SRV_LOG_SPACE_FIRST_ID) {
2011-07-14 21:22:41 +02:00
index->table->is_corrupt = TRUE;
fil_space_set_corrupt(index->table->space);
}
if ((srv_force_recovery == 0 || moves_up == FALSE)
&& srv_pass_corrupt_table <= 1) {
ut_print_timestamp(stderr);
buf_page_print(page_align(rec), 0,
BUF_PAGE_PRINT_NO_CRASH);
fprintf(stderr,
"\nInnoDB: rec address %p,"
" buf block fix count %lu\n",
(void*) rec, (ulong)
btr_cur_get_block(btr_pcur_get_btr_cur(pcur))
->page.buf_fix_count);
fprintf(stderr,
"InnoDB: Index corruption: rec offs %lu"
" next offs %lu, page no %lu,\n"
"InnoDB: ",
(ulong) page_offset(rec),
(ulong) next_offs,
(ulong) page_get_page_no(page_align(rec)));
dict_index_name_print(stderr, trx, index);
fputs(". Run CHECK TABLE. You may need to\n"
"InnoDB: restore from a backup, or"
" dump + drop + reimport the table.\n",
stderr);
ut_ad(0);
err = DB_CORRUPTION;
goto lock_wait_or_error;
} else {
/* The user may be dumping a corrupt table. Jump
over the corruption to recover as much as possible. */
fprintf(stderr,
"InnoDB: Index corruption: rec offs %lu"
" next offs %lu, page no %lu,\n"
"InnoDB: ",
(ulong) page_offset(rec),
(ulong) next_offs,
(ulong) page_get_page_no(page_align(rec)));
dict_index_name_print(stderr, trx, index);
fputs(". We try to skip the rest of the page.\n",
stderr);
btr_pcur_move_to_last_on_page(pcur, &mtr);
goto next_rec;
}
}
/*-------------------------------------------------------------*/
/* Calculate the 'offsets' associated with 'rec' */
2013-12-16 15:38:05 +01:00
ut_ad(fil_page_get_type(btr_pcur_get_page(pcur)) == FIL_PAGE_INDEX);
ut_ad(btr_page_get_index_id(btr_pcur_get_page(pcur)) == index->id);
offsets = rec_get_offsets(rec, index, offsets, ULINT_UNDEFINED, &heap);
2013-05-08 09:52:54 +02:00
if (UNIV_UNLIKELY(srv_force_recovery > 0
|| (index->table->is_corrupt &&
srv_pass_corrupt_table == 2))) {
if (!rec_validate(rec, offsets)
|| !btr_index_rec_validate(rec, index, FALSE)) {
fprintf(stderr,
"InnoDB: Index corruption: rec offs %lu"
" next offs %lu, page no %lu,\n"
"InnoDB: ",
(ulong) page_offset(rec),
(ulong) next_offs,
(ulong) page_get_page_no(page_align(rec)));
dict_index_name_print(stderr, trx, index);
fputs(". We try to skip the record.\n",
stderr);
goto next_rec;
}
}
/* Note that we cannot trust the up_match value in the cursor at this
place because we can arrive here after moving the cursor! Thus
we have to recompare rec and search_tuple to determine if they
match enough. */
if (match_mode == ROW_SEL_EXACT) {
/* Test if the index record matches completely to search_tuple
in prebuilt: if not, then we return with DB_RECORD_NOT_FOUND */
/* fputs("Comparing rec and search tuple\n", stderr); */
if (0 != cmp_dtuple_rec(search_tuple, rec, offsets)) {
if (set_also_gap_locks
&& !(srv_locks_unsafe_for_binlog
|| trx->isolation_level
<= TRX_ISO_READ_COMMITTED)
&& prebuilt->select_lock_type != LOCK_NONE) {
/* Try to place a gap lock on the index
record only if innodb_locks_unsafe_for_binlog
option is not set or this session is not
using a READ COMMITTED or lower isolation level. */
err = sel_set_rec_lock(
btr_pcur_get_block(pcur),
rec, index, offsets,
prebuilt->select_lock_type, LOCK_GAP,
thr);
switch (err) {
case DB_SUCCESS_LOCKED_REC:
case DB_SUCCESS:
break;
default:
goto lock_wait_or_error;
}
}
btr_pcur_store_position(pcur, &mtr);
2014-02-26 16:25:11 +01:00
/* The found record was not a match, but may be used
as NEXT record (index_next). Set the relative position
to BTR_PCUR_BEFORE, to reflect that the position of
the persistent cursor is before the found/stored row
(pcur->old_rec). */
ut_ad(pcur->rel_pos == BTR_PCUR_ON);
pcur->rel_pos = BTR_PCUR_BEFORE;
err = DB_RECORD_NOT_FOUND;
2013-12-16 15:38:05 +01:00
#if 0
ut_print_name(stderr, trx, FALSE, index->name);
fputs(" record not found 3\n", stderr);
#endif
goto normal_return;
}
} else if (match_mode == ROW_SEL_EXACT_PREFIX) {
if (!cmp_dtuple_is_prefix_of_rec(search_tuple, rec, offsets)) {
if (set_also_gap_locks
&& !(srv_locks_unsafe_for_binlog
|| trx->isolation_level
<= TRX_ISO_READ_COMMITTED)
&& prebuilt->select_lock_type != LOCK_NONE) {
/* Try to place a gap lock on the index
record only if innodb_locks_unsafe_for_binlog
option is not set or this session is not
using a READ COMMITTED or lower isolation level. */
err = sel_set_rec_lock(
btr_pcur_get_block(pcur),
rec, index, offsets,
prebuilt->select_lock_type, LOCK_GAP,
thr);
switch (err) {
case DB_SUCCESS_LOCKED_REC:
case DB_SUCCESS:
break;
default:
goto lock_wait_or_error;
}
}
btr_pcur_store_position(pcur, &mtr);
2014-02-26 16:25:11 +01:00
/* The found record was not a match, but may be used
as NEXT record (index_next). Set the relative position
to BTR_PCUR_BEFORE, to reflect that the position of
the persistent cursor is before the found/stored row
(pcur->old_rec). */
ut_ad(pcur->rel_pos == BTR_PCUR_ON);
pcur->rel_pos = BTR_PCUR_BEFORE;
err = DB_RECORD_NOT_FOUND;
2013-12-16 15:38:05 +01:00
#if 0
ut_print_name(stderr, trx, FALSE, index->name);
fputs(" record not found 4\n", stderr);
#endif
goto normal_return;
}
}
/* We are ready to look at a possible new index entry in the result
set: the cursor is now placed on a user record */
if (prebuilt->select_lock_type != LOCK_NONE) {
/* Try to place a lock on the index record; note that delete
marked records are a special case in a unique search. If there
is a non-delete marked record, then it is enough to lock its
existence with LOCK_REC_NOT_GAP. */
/* If innodb_locks_unsafe_for_binlog option is used
or this session is using a READ COMMITED isolation
level we lock only the record, i.e., next-key locking is
not used. */
ulint lock_type;
if (!set_also_gap_locks
|| srv_locks_unsafe_for_binlog
|| trx->isolation_level <= TRX_ISO_READ_COMMITTED
2013-12-16 15:38:05 +01:00
|| (unique_search && !rec_get_deleted_flag(rec, comp))) {
goto no_gap_lock;
} else {
lock_type = LOCK_ORDINARY;
}
/* If we are doing a 'greater or equal than a primary key
value' search from a clustered index, and we find a record
that has that exact primary key value, then there is no need
to lock the gap before the record, because no insert in the
gap can be in our search range. That is, no phantom row can
appear that way.
An example: if col1 is the primary key, the search is WHERE
col1 >= 100, and we find a record where col1 = 100, then no
need to lock the gap before that record. */
if (index == clust_index
&& mode == PAGE_CUR_GE
&& direction == 0
&& dtuple_get_n_fields_cmp(search_tuple)
== dict_index_get_n_unique(index)
&& 0 == cmp_dtuple_rec(search_tuple, rec, offsets)) {
no_gap_lock:
lock_type = LOCK_REC_NOT_GAP;
}
err = sel_set_rec_lock(btr_pcur_get_block(pcur),
rec, index, offsets,
prebuilt->select_lock_type,
lock_type, thr);
switch (err) {
const rec_t* old_vers;
case DB_SUCCESS_LOCKED_REC:
2009-08-09 09:04:58 +02:00
if (srv_locks_unsafe_for_binlog
|| trx->isolation_level
<= TRX_ISO_READ_COMMITTED) {
2009-08-09 09:04:58 +02:00
/* Note that a record of
prebuilt->index was locked. */
prebuilt->new_rec_locks = 1;
}
err = DB_SUCCESS;
case DB_SUCCESS:
break;
case DB_LOCK_WAIT:
/* Never unlock rows that were part of a conflict. */
prebuilt->new_rec_locks = 0;
if (UNIV_LIKELY(prebuilt->row_read_type
!= ROW_READ_TRY_SEMI_CONSISTENT)
|| unique_search
|| index != clust_index) {
goto lock_wait_or_error;
}
/* The following call returns 'offsets'
associated with 'old_vers' */
2013-12-16 15:38:05 +01:00
row_sel_build_committed_vers_for_mysql(
clust_index, prebuilt, rec,
&offsets, &heap, &old_vers, &mtr);
2013-12-16 15:38:05 +01:00
/* Check whether it was a deadlock or not, if not
a deadlock and the transaction had to wait then
release the lock it is waiting on. */
2013-12-16 15:38:05 +01:00
err = lock_trx_handle_wait(trx);
2013-12-16 15:38:05 +01:00
switch (err) {
case DB_SUCCESS:
/* The lock was granted while we were
searching for the last committed version.
Do a normal locking read. */
2013-12-16 15:38:05 +01:00
offsets = rec_get_offsets(
rec, index, offsets, ULINT_UNDEFINED,
&heap);
goto locks_ok;
case DB_DEADLOCK:
goto lock_wait_or_error;
2013-12-16 15:38:05 +01:00
case DB_LOCK_WAIT:
err = DB_SUCCESS;
break;
2013-12-16 15:38:05 +01:00
default:
ut_error;
}
if (old_vers == NULL) {
/* The row was not yet committed */
goto next_rec;
}
did_semi_consistent_read = TRUE;
rec = old_vers;
break;
default:
goto lock_wait_or_error;
}
} else {
/* This is a non-locking consistent read: if necessary, fetch
a previous version of the record */
if (trx->isolation_level == TRX_ISO_READ_UNCOMMITTED) {
/* Do nothing: we let a non-locking SELECT read the
latest version of the record */
} else if (index == clust_index) {
/* Fetch a previous version of the row if the current
one is not visible in the snapshot; if we have a very
high force recovery level set, we try to avoid crashes
by skipping this lookup */
if (UNIV_LIKELY(srv_force_recovery < 5)
&& !lock_clust_rec_cons_read_sees(
rec, index, offsets, trx->read_view)) {
rec_t* old_vers;
/* The following call returns 'offsets'
associated with 'old_vers' */
err = row_sel_build_prev_vers_for_mysql(
trx->read_view, clust_index,
prebuilt, rec, &offsets, &heap,
&old_vers, &mtr);
if (err != DB_SUCCESS) {
goto lock_wait_or_error;
}
if (old_vers == NULL) {
/* The row did not exist yet in
the read view */
goto next_rec;
}
rec = old_vers;
}
} else {
/* We are looking into a non-clustered index,
and to get the right version of the record we
have to look also into the clustered index: this
is necessary, because we can only get the undo
information via the clustered index record. */
ut_ad(!dict_index_is_clust(index));
if (!lock_sec_rec_cons_read_sees(
rec, trx->read_view)) {
/* We should look at the clustered index.
However, as this is a non-locking read,
we can skip the clustered index lookup if
the condition does not match the secondary
index entry. */
switch (row_search_idx_cond_check(
buf, prebuilt, rec, offsets)) {
case ICP_NO_MATCH:
goto next_rec;
case ICP_OUT_OF_RANGE:
err = DB_RECORD_NOT_FOUND;
goto idx_cond_failed;
case ICP_ABORTED_BY_USER:
err = DB_SEARCH_ABORTED_BY_USER;
goto idx_cond_failed;
case ICP_ERROR:
err = DB_ERROR;
goto idx_cond_failed;
case ICP_MATCH:
goto requires_clust_rec;
}
ut_error;
}
}
}
2013-12-16 15:38:05 +01:00
locks_ok:
/* NOTE that at this point rec can be an old version of a clustered
index record built for a consistent read. We cannot assume after this
point that rec is on a buffer pool page. Functions like
page_rec_is_comp() cannot be used! */
2013-12-16 15:38:05 +01:00
if (rec_get_deleted_flag(rec, comp)) {
/* The record is delete-marked: we can skip it */
if ((srv_locks_unsafe_for_binlog
|| trx->isolation_level <= TRX_ISO_READ_COMMITTED)
&& prebuilt->select_lock_type != LOCK_NONE
&& !did_semi_consistent_read) {
/* No need to keep a lock on a delete-marked record
if we do not want to use next-key locking. */
row_unlock_for_mysql(prebuilt, TRUE);
}
/* This is an optimization to skip setting the next key lock
on the record that follows this delete-marked record. This
optimization works because of the unique search criteria
which precludes the presence of a range lock between this
delete marked record and the record following it.
For now this is applicable only to clustered indexes while
2013-12-16 15:38:05 +01:00
doing a unique search except for HANDLER queries because
HANDLER allows NEXT and PREV even in unique search on
clustered index. There is scope for further optimization
applicable to unique secondary indexes. Current behaviour is
to widen the scope of a lock on an already delete marked record
if the same record is deleted twice by the same transaction */
if (index == clust_index && unique_search
&& !prebuilt->used_in_HANDLER) {
err = DB_RECORD_NOT_FOUND;
goto normal_return;
}
goto next_rec;
}
/* Check if the record matches the index condition. */
switch (row_search_idx_cond_check(buf, prebuilt, rec, offsets)) {
case ICP_NO_MATCH:
if (did_semi_consistent_read) {
row_unlock_for_mysql(prebuilt, TRUE);
2013-12-16 15:38:05 +01:00
}
goto next_rec;
case ICP_ABORTED_BY_USER:
err = DB_SEARCH_ABORTED_BY_USER;
goto idx_cond_failed;
case ICP_ERROR:
err = DB_ERROR;
goto idx_cond_failed;
case ICP_OUT_OF_RANGE:
err = DB_RECORD_NOT_FOUND;
goto idx_cond_failed;
case ICP_MATCH:
break;
2013-12-16 15:38:05 +01:00
}
/* Get the clustered index record if needed, if we did not do the
search using the clustered index... */
use_clustered_index =
(index != clust_index && prebuilt->need_to_access_clustered);
if (use_clustered_index && srv_prefix_index_cluster_optimization
&& prebuilt->n_template <= index->n_fields) {
/* ...but, perhaps avoid the clustered index lookup if
all of the following are true:
1) all columns are in the secondary index
2) all values for columns that are prefix-only
indexes are shorter than the prefix size
This optimization can avoid many IOs for certain schemas.
*/
ibool row_contains_all_values = TRUE;
int i;
for (i = 0; i < prebuilt->n_template; i++) {
/* Condition (1) from above: is the field in the
index (prefix or not)? */
mysql_row_templ_t* templ =
prebuilt->mysql_template + i;
ulint secondary_index_field_no =
templ->rec_prefix_field_no;
if (secondary_index_field_no == ULINT_UNDEFINED) {
row_contains_all_values = FALSE;
break;
}
/* Condition (2) from above: if this is a
prefix, is this row's value size shorter
than the prefix? */
if (templ->rec_field_is_prefix) {
ulint record_size = rec_offs_nth_size(
offsets,
secondary_index_field_no);
const dict_field_t *field =
dict_index_get_nth_field(
index,
secondary_index_field_no);
ut_a(field->prefix_len > 0);
if (record_size >= field->prefix_len) {
row_contains_all_values = FALSE;
break;
}
}
}
/* If (1) and (2) were true for all columns above, use
rec_prefix_field_no instead of rec_field_no, and skip
the clustered lookup below. */
if (row_contains_all_values) {
for (i = 0; i < prebuilt->n_template; i++) {
mysql_row_templ_t* templ =
prebuilt->mysql_template + i;
templ->rec_field_no =
templ->rec_prefix_field_no;
ut_a(templ->rec_field_no != ULINT_UNDEFINED);
}
use_clustered_index = FALSE;
srv_stats.n_sec_rec_cluster_reads_avoided.inc();
}
}
if (use_clustered_index) {
requires_clust_rec:
ut_ad(index != clust_index);
/* We use a 'goto' to the preceding label if a consistent
read of a secondary index record requires us to look up old
versions of the associated clustered index record. */
ut_ad(rec_offs_validate(rec, index, offsets));
/* It was a non-clustered index and we must fetch also the
clustered index record */
mtr_has_extra_clust_latch = TRUE;
/* The following call returns 'offsets' associated with
'clust_rec'. Note that 'clust_rec' can be an old version
built for a consistent read. */
err = row_sel_get_clust_rec_for_mysql(prebuilt, index, rec,
thr, &clust_rec,
&offsets, &heap, &mtr);
switch (err) {
case DB_SUCCESS:
if (clust_rec == NULL) {
/* The record did not exist in the read view */
ut_ad(prebuilt->select_lock_type == LOCK_NONE);
goto next_rec;
}
break;
case DB_SUCCESS_LOCKED_REC:
ut_a(clust_rec != NULL);
if (srv_locks_unsafe_for_binlog
|| trx->isolation_level
<= TRX_ISO_READ_COMMITTED) {
/* Note that the clustered index record
was locked. */
prebuilt->new_rec_locks = 2;
}
err = DB_SUCCESS;
break;
default:
goto lock_wait_or_error;
}
2013-12-16 15:38:05 +01:00
if (rec_get_deleted_flag(clust_rec, comp)) {
/* The record is delete marked: we can skip it */
if ((srv_locks_unsafe_for_binlog
|| trx->isolation_level <= TRX_ISO_READ_COMMITTED)
&& prebuilt->select_lock_type != LOCK_NONE) {
/* No need to keep a lock on a delete-marked
record if we do not want to use next-key
locking. */
row_unlock_for_mysql(prebuilt, TRUE);
}
goto next_rec;
}
result_rec = clust_rec;
ut_ad(rec_offs_validate(result_rec, clust_index, offsets));
if (prebuilt->idx_cond) {
2013-12-16 15:38:05 +01:00
/* Convert the record to MySQL format. We were
unable to do this in row_search_idx_cond_check(),
because the condition is on the secondary index
and the requested column is in the clustered index.
We convert all fields, including those that
may have been used in ICP, because the
secondary index may contain a column prefix
rather than the full column. Also, as noted
in Bug #56680, the column in the secondary
index may be in the wrong case, and the
authoritative case is in result_rec, the
appropriate version of the clustered index record. */
if (!row_sel_store_mysql_rec(
buf, prebuilt, result_rec,
TRUE, clust_index, offsets)) {
goto next_rec;
}
}
} else {
result_rec = rec;
}
/* We found a qualifying record 'result_rec'. At this point,
'offsets' are associated with 'result_rec'. */
ut_ad(rec_offs_validate(result_rec,
result_rec != rec ? clust_index : index,
offsets));
ut_ad(!rec_get_deleted_flag(result_rec, comp));
/* At this point, the clustered index record is protected
by a page latch that was acquired when pcur was positioned.
The latch will not be released until mtr_commit(&mtr). */
if ((match_mode == ROW_SEL_EXACT
|| prebuilt->n_rows_fetched >= MYSQL_FETCH_CACHE_THRESHOLD)
&& prebuilt->select_lock_type == LOCK_NONE
&& !prebuilt->templ_contains_blob
&& !prebuilt->clust_index_was_generated
&& !prebuilt->used_in_HANDLER
2013-12-16 15:38:05 +01:00
&& !prebuilt->innodb_api
&& prebuilt->template_type
2013-12-16 15:38:05 +01:00
!= ROW_MYSQL_DUMMY_TEMPLATE
&& !prebuilt->in_fts_query) {
/* Inside an update, for example, we do not cache rows,
since we may use the cursor position to do the actual
update, that is why we require ...lock_type == LOCK_NONE.
Since we keep space in prebuilt only for the BLOBs of
a single row, we cannot cache rows in the case there
are BLOBs in the fields to be fetched. In HANDLER we do
not cache rows because there the cursor is a scrollable
cursor. */
2013-12-16 15:38:05 +01:00
ut_a(prebuilt->n_fetch_cached < MYSQL_FETCH_CACHE_SIZE);
/* We only convert from InnoDB row format to MySQL row
format when ICP is disabled. */
2013-12-16 15:38:05 +01:00
if (!prebuilt->idx_cond) {
2013-12-16 15:38:05 +01:00
/* We use next_buf to track the allocation of buffers
where we store and enqueue the buffers for our
pre-fetch optimisation.
If next_buf == 0 then we store the converted record
directly into the MySQL record buffer (buf). If it is
!= 0 then we allocate a pre-fetch buffer and store the
converted record there.
If the conversion fails and the MySQL record buffer
was not written to then we reset next_buf so that
we can re-use the MySQL record buffer in the next
iteration. */
next_buf = next_buf
? row_sel_fetch_last_buf(prebuilt) : buf;
if (!row_sel_store_mysql_rec(
next_buf, prebuilt, result_rec,
result_rec != rec,
result_rec != rec ? clust_index : index,
offsets)) {
if (next_buf == buf) {
ut_a(prebuilt->n_fetch_cached == 0);
next_buf = 0;
}
/* Only fresh inserts may contain incomplete
externally stored columns. Pretend that such
records do not exist. Such records may only be
accessed at the READ UNCOMMITTED isolation
level or when rolling back a recovered
transaction. Rollback happens at a lower
level, not here. */
goto next_rec;
}
if (next_buf != buf) {
row_sel_enqueue_cache_row_for_mysql(
next_buf, prebuilt);
}
} else {
row_sel_enqueue_cache_row_for_mysql(buf, prebuilt);
}
2013-12-16 15:38:05 +01:00
if (prebuilt->n_fetch_cached < MYSQL_FETCH_CACHE_SIZE) {
goto next_rec;
}
} else {
if (UNIV_UNLIKELY
(prebuilt->template_type == ROW_MYSQL_DUMMY_TEMPLATE)) {
/* CHECK TABLE: fetch the row */
if (result_rec != rec
&& !prebuilt->need_to_access_clustered) {
/* We used 'offsets' for the clust
rec, recalculate them for 'rec' */
offsets = rec_get_offsets(rec, index, offsets,
ULINT_UNDEFINED,
&heap);
result_rec = rec;
}
memcpy(buf + 4, result_rec
- rec_offs_extra_size(offsets),
rec_offs_size(offsets));
mach_write_to_4(buf,
rec_offs_extra_size(offsets) + 4);
2013-12-16 15:38:05 +01:00
} else if (!prebuilt->idx_cond && !prebuilt->innodb_api) {
/* The record was not yet converted to MySQL format. */
if (!row_sel_store_mysql_rec(
2013-12-16 15:38:05 +01:00
buf, prebuilt, result_rec,
result_rec != rec,
result_rec != rec ? clust_index : index,
offsets)) {
/* Only fresh inserts may contain
incomplete externally stored
columns. Pretend that such records do
not exist. Such records may only be
accessed at the READ UNCOMMITTED
isolation level or when rolling back a
recovered transaction. Rollback
happens at a lower level, not here. */
goto next_rec;
}
}
if (prebuilt->clust_index_was_generated) {
2013-12-16 15:38:05 +01:00
row_sel_store_row_id_to_prebuilt(
prebuilt, result_rec,
result_rec == rec ? index : clust_index,
offsets);
}
}
/* From this point on, 'offsets' are invalid. */
/* We have an optimization to save CPU time: if this is a consistent
read on a unique condition on the clustered index, then we do not
store the pcur position, because any fetch next or prev will anyway
return 'end of file'. Exceptions are locking reads and the MySQL
HANDLER command where the user can move the cursor with PREV or NEXT
even after a unique search. */
err = DB_SUCCESS;
idx_cond_failed:
2013-12-16 15:38:05 +01:00
if (!unique_search
|| !dict_index_is_clust(index)
|| direction != 0
|| prebuilt->select_lock_type != LOCK_NONE
2013-12-16 15:38:05 +01:00
|| prebuilt->used_in_HANDLER
|| prebuilt->innodb_api) {
/* Inside an update always store the cursor position */
btr_pcur_store_position(pcur, &mtr);
2013-12-16 15:38:05 +01:00
if (prebuilt->innodb_api) {
prebuilt->innodb_api_rec = result_rec;
}
}
goto normal_return;
next_rec:
/* Reset the old and new "did semi-consistent read" flags. */
if (UNIV_UNLIKELY(prebuilt->row_read_type
== ROW_READ_DID_SEMI_CONSISTENT)) {
prebuilt->row_read_type = ROW_READ_TRY_SEMI_CONSISTENT;
}
did_semi_consistent_read = FALSE;
2009-08-09 09:04:58 +02:00
prebuilt->new_rec_locks = 0;
/*-------------------------------------------------------------*/
/* PHASE 5: Move the cursor to the next index record */
2013-12-16 15:38:05 +01:00
/* NOTE: For moves_up==FALSE, the mini-transaction will be
committed and restarted every time when switching b-tree
pages. For moves_up==TRUE in index condition pushdown, we can
scan an entire secondary index tree within a single
mini-transaction. As long as the prebuilt->idx_cond does not
match, we do not need to consult the clustered index or
return records to MySQL, and thus we can avoid repositioning
the cursor. What prevents us from buffer-fixing all leaf pages
within the mini-transaction is the btr_leaf_page_release()
call in btr_pcur_move_to_next_page(). Only the leaf page where
the cursor is positioned will remain buffer-fixed. */
if (UNIV_UNLIKELY(mtr_has_extra_clust_latch)) {
/* We must commit mtr if we are moving to the next
non-clustered index record, because we could break the
latching order if we would access a different clustered
index page right away without releasing the previous. */
btr_pcur_store_position(pcur, &mtr);
mtr_commit(&mtr);
mtr_has_extra_clust_latch = FALSE;
mtr_start_trx(&mtr, trx);
if (sel_restore_position_for_mysql(&same_user_rec,
BTR_SEARCH_LEAF,
pcur, moves_up, &mtr)) {
#ifdef UNIV_SEARCH_DEBUG
cnt++;
#endif /* UNIV_SEARCH_DEBUG */
goto rec_loop;
}
}
if (moves_up) {
if (UNIV_UNLIKELY(!btr_pcur_move_to_next(pcur, &mtr))) {
not_moved:
btr_pcur_store_position(pcur, &mtr);
if (match_mode != 0) {
err = DB_RECORD_NOT_FOUND;
} else {
err = DB_END_OF_INDEX;
}
goto normal_return;
}
} else {
if (UNIV_UNLIKELY(!btr_pcur_move_to_prev(pcur, &mtr))) {
goto not_moved;
}
}
#ifdef UNIV_SEARCH_DEBUG
cnt++;
#endif /* UNIV_SEARCH_DEBUG */
goto rec_loop;
lock_wait_or_error:
/* Reset the old and new "did semi-consistent read" flags. */
if (UNIV_UNLIKELY(prebuilt->row_read_type
== ROW_READ_DID_SEMI_CONSISTENT)) {
prebuilt->row_read_type = ROW_READ_TRY_SEMI_CONSISTENT;
}
did_semi_consistent_read = FALSE;
/*-------------------------------------------------------------*/
if (rec) {
btr_pcur_store_position(pcur, &mtr);
}
lock_table_wait:
mtr_commit(&mtr);
mtr_has_extra_clust_latch = FALSE;
trx->error_state = err;
/* The following is a patch for MySQL */
que_thr_stop_for_mysql(thr);
thr->lock_state = QUE_THR_LOCK_ROW;
if (row_mysql_handle_errors(&err, trx, thr, NULL)) {
/* It was a lock wait, and it ended */
thr->lock_state = QUE_THR_LOCK_NOLOCK;
mtr_start_trx(&mtr, trx);
/* Table lock waited, go try to obtain table lock
again */
if (table_lock_waited) {
table_lock_waited = FALSE;
goto wait_table_again;
}
sel_restore_position_for_mysql(&same_user_rec,
BTR_SEARCH_LEAF, pcur,
moves_up, &mtr);
if ((srv_locks_unsafe_for_binlog
|| trx->isolation_level <= TRX_ISO_READ_COMMITTED)
&& !same_user_rec) {
/* Since we were not able to restore the cursor
on the same user record, we cannot use
row_unlock_for_mysql() to unlock any records, and
we must thus reset the new rec lock info. Since
2013-12-16 15:38:05 +01:00
in lock0lock.cc we have blocked the inheriting of gap
X-locks, we actually do not have any new record locks
set in this case.
Note that if we were able to restore on the 'same'
user record, it is still possible that we were actually
waiting on a delete-marked record, and meanwhile
it was removed by purge and inserted again by some
other user. But that is no problem, because in
rec_loop we will again try to set a lock, and
new_rec_lock_info in trx will be right at the end. */
2009-08-09 09:04:58 +02:00
prebuilt->new_rec_locks = 0;
}
mode = pcur->search_mode;
goto rec_loop;
}
thr->lock_state = QUE_THR_LOCK_NOLOCK;
#ifdef UNIV_SEARCH_DEBUG
/* fputs("Using ", stderr);
dict_index_name_print(stderr, index);
fprintf(stderr, " cnt %lu ret value %lu err\n", cnt, err); */
#endif /* UNIV_SEARCH_DEBUG */
goto func_exit;
normal_return:
/*-------------------------------------------------------------*/
que_thr_stop_for_mysql_no_error(thr, trx);
mtr_commit(&mtr);
2013-12-16 15:38:05 +01:00
if (prebuilt->idx_cond != 0) {
/* When ICP is active we don't write to the MySQL buffer
directly, only to buffers that are enqueued in the pre-fetch
queue. We need to dequeue the first buffer and copy the contents
to the record buffer that was passed in by MySQL. */
if (prebuilt->n_fetch_cached > 0) {
row_sel_dequeue_cached_row_for_mysql(buf, prebuilt);
err = DB_SUCCESS;
}
} else if (next_buf != 0) {
/* We may or may not have enqueued some buffers to the
pre-fetch queue, but we definitely wrote to the record
buffer passed to use by MySQL. */
2014-02-26 16:25:11 +01:00
DEBUG_SYNC_C("row_search_cached_row");
err = DB_SUCCESS;
}
#ifdef UNIV_SEARCH_DEBUG
/* fputs("Using ", stderr);
dict_index_name_print(stderr, index);
fprintf(stderr, " cnt %lu ret value %lu err\n", cnt, err); */
#endif /* UNIV_SEARCH_DEBUG */
func_exit:
trx->op_info = "";
if (UNIV_LIKELY_NULL(heap)) {
mem_heap_free(heap);
}
/* Set or reset the "did semi-consistent read" flag on return.
The flag did_semi_consistent_read is set if and only if
the record being returned was fetched with a semi-consistent read. */
ut_ad(prebuilt->row_read_type != ROW_READ_WITH_LOCKS
|| !did_semi_consistent_read);
if (UNIV_UNLIKELY(prebuilt->row_read_type != ROW_READ_WITH_LOCKS)) {
if (UNIV_UNLIKELY(did_semi_consistent_read)) {
prebuilt->row_read_type = ROW_READ_DID_SEMI_CONSISTENT;
} else {
prebuilt->row_read_type = ROW_READ_TRY_SEMI_CONSISTENT;
}
}
2011-07-14 21:22:41 +02:00
2013-11-07 21:44:46 +01:00
ut_ad(!trx->has_search_latch);
2011-07-14 21:22:41 +02:00
#ifdef UNIV_SYNC_DEBUG
2013-11-07 21:44:46 +01:00
ut_ad(!btr_search_own_any());
2011-07-14 21:22:41 +02:00
ut_ad(!sync_thread_levels_nonempty_trx(trx->has_search_latch));
#endif /* UNIV_SYNC_DEBUG */
2013-12-16 15:38:05 +01:00
DEBUG_SYNC_C("innodb_row_search_for_mysql_exit");
return(err);
}
2009-09-07 12:22:53 +02:00
/*******************************************************************//**
Checks if MySQL at the moment is allowed for this table to retrieve a
2009-09-07 12:22:53 +02:00
consistent read result, or store it to the query cache.
@return TRUE if storing or retrieving from the query cache is permitted */
UNIV_INTERN
ibool
row_search_check_if_query_cache_permitted(
/*======================================*/
2009-09-07 12:22:53 +02:00
trx_t* trx, /*!< in: transaction object */
const char* norm_name) /*!< in: concatenation of database name,
'/' char, table name */
{
dict_table_t* table;
ibool ret = FALSE;
2013-12-16 15:38:05 +01:00
/* Disable query cache altogether for all tables if recovered XA
transactions in prepared state exist. This is because we do not
restore the table locks for those transactions and we may wrongly
set ret=TRUE above if "lock_table_get_n_locks(table) == 0". See
"Bug#14658648 XA ROLLBACK (DISTRIBUTED DATABASE) NOT WORKING WITH
QUERY CACHE ENABLED".
Read trx_sys->n_prepared_recovered_trx without mutex protection,
not possible to end up with a torn read since n_prepared_recovered_trx
is word size. */
if (trx_sys->n_prepared_recovered_trx > 0) {
return(FALSE);
}
table = dict_table_open_on_name(norm_name, FALSE, FALSE,
DICT_ERR_IGNORE_NONE);
if (table == NULL) {
return(FALSE);
}
/* Start the transaction if it is not started yet */
2013-12-16 15:38:05 +01:00
trx_start_if_not_started(trx);
/* If there are locks on the table or some trx has invalidated the
cache up to our trx id, then ret = FALSE.
We do not check what type locks there are on the table, though only
IX type locks actually would require ret = FALSE. */
2013-12-16 15:38:05 +01:00
if (lock_table_get_n_locks(table) == 0
2011-07-14 21:22:41 +02:00
&& trx->id >= table->query_cache_inv_trx_id) {
ret = TRUE;
/* If the isolation level is high, assign a read view for the
transaction if it does not yet have one */
if (trx->isolation_level >= TRX_ISO_REPEATABLE_READ
&& !trx->read_view) {
2013-05-08 09:52:54 +02:00
trx->read_view =
read_view_open_now(trx->id,
2013-12-16 15:38:05 +01:00
trx->prebuilt_view);
trx->global_read_view = trx->read_view;
}
}
2013-12-16 15:38:05 +01:00
dict_table_close(table, FALSE, FALSE);
return(ret);
}
2009-09-07 12:22:53 +02:00
/*******************************************************************//**
Read the AUTOINC column from the current row. If the value is less than
2009-09-07 12:22:53 +02:00
0 and the type is not unsigned then we reset the value to 0.
@return value read from the column */
static
ib_uint64_t
row_search_autoinc_read_column(
/*===========================*/
2009-09-07 12:22:53 +02:00
dict_index_t* index, /*!< in: index to read from */
const rec_t* rec, /*!< in: current rec */
ulint col_no, /*!< in: column number */
ulint mtype, /*!< in: column main type */
2009-09-07 12:22:53 +02:00
ibool unsigned_type) /*!< in: signed or unsigned flag */
{
ulint len;
const byte* data;
ib_uint64_t value;
mem_heap_t* heap = NULL;
ulint offsets_[REC_OFFS_NORMAL_SIZE];
ulint* offsets = offsets_;
rec_offs_init(offsets_);
2013-02-28 22:23:45 +01:00
offsets = rec_get_offsets(rec, index, offsets, col_no + 1, &heap);
2013-02-28 22:23:45 +01:00
if (rec_offs_nth_sql_null(offsets, col_no)) {
/* There is no non-NULL value in the auto-increment column. */
value = 0;
goto func_exit;
}
2013-02-28 22:23:45 +01:00
data = rec_get_nth_field(rec, offsets, col_no, &len);
switch (mtype) {
case DATA_INT:
ut_a(len <= sizeof value);
value = mach_read_int_type(data, len, unsigned_type);
break;
case DATA_FLOAT:
ut_a(len == sizeof(float));
value = (ib_uint64_t) mach_float_read(data);
break;
case DATA_DOUBLE:
ut_a(len == sizeof(double));
value = (ib_uint64_t) mach_double_read(data);
break;
default:
ut_error;
}
if (!unsigned_type && (ib_int64_t) value < 0) {
value = 0;
}
2013-02-28 22:23:45 +01:00
func_exit:
if (UNIV_LIKELY_NULL(heap)) {
mem_heap_free(heap);
}
return(value);
}
2014-05-05 18:16:30 +02:00
/** Get the maximum and non-delete-marked record in an index.
@param[in] index index tree
@param[in,out] mtr mini-transaction (may be committed and restarted)
@return maximum record, page s-latched in mtr
@retval NULL if there are no records, or if all of them are delete-marked */
static
const rec_t*
2014-05-05 18:16:30 +02:00
row_search_get_max_rec(
dict_index_t* index,
mtr_t* mtr)
{
2014-05-05 18:16:30 +02:00
btr_pcur_t pcur;
const rec_t* rec;
/* Open at the high/right end (false), and init cursor */
btr_pcur_open_at_index_side(
false, index, BTR_SEARCH_LEAF, &pcur, true, 0, mtr);
do {
2014-05-05 18:16:30 +02:00
const page_t* page;
page = btr_pcur_get_page(&pcur);
rec = page_find_rec_max_not_deleted(page);
if (page_rec_is_user_rec(rec)) {
2014-05-05 18:16:30 +02:00
break;
} else {
rec = NULL;
}
2014-05-05 18:16:30 +02:00
btr_pcur_move_before_first_on_page(&pcur);
} while (btr_pcur_move_to_prev(&pcur, mtr));
2014-05-05 18:16:30 +02:00
btr_pcur_close(&pcur);
return(rec);
}
2009-09-07 12:22:53 +02:00
/*******************************************************************//**
Read the max AUTOINC value from an index.
@return DB_SUCCESS if all OK else error code, DB_RECORD_NOT_FOUND if
column name can't be found in index */
UNIV_INTERN
2013-12-16 15:38:05 +01:00
dberr_t
row_search_max_autoinc(
/*===================*/
2009-09-07 12:22:53 +02:00
dict_index_t* index, /*!< in: index to search */
const char* col_name, /*!< in: name of autoinc column */
ib_uint64_t* value) /*!< out: AUTOINC value read */
{
2014-05-05 18:16:30 +02:00
dict_field_t* dfield = dict_index_get_nth_field(index, 0);
2013-12-16 15:38:05 +01:00
dberr_t error = DB_SUCCESS;
*value = 0;
2014-05-05 18:16:30 +02:00
if (strcmp(col_name, dfield->name) != 0) {
error = DB_RECORD_NOT_FOUND;
} else {
mtr_t mtr;
2014-05-05 18:16:30 +02:00
const rec_t* rec;
mtr_start(&mtr);
2014-05-05 18:16:30 +02:00
rec = row_search_get_max_rec(index, &mtr);
2014-05-05 18:16:30 +02:00
if (rec != NULL) {
ibool unsigned_type = (
dfield->col->prtype & DATA_UNSIGNED);
2014-05-05 18:16:30 +02:00
*value = row_search_autoinc_read_column(
index, rec, 0,
dfield->col->mtype, unsigned_type);
}
mtr_commit(&mtr);
}
return(error);
}