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mariadb/sql/sql_update.cc

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/* Copyright (c) 2000, 2016, Oracle and/or its affiliates.
Copyright (c) 2011, 2022, MariaDB
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 this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335 USA */
/*
Single table and multi table updates of tables.
Multi-table updates were introduced by Sinisa & Monty
*/
#include "mariadb.h" /* NO_EMBEDDED_ACCESS_CHECKS */
#include "sql_priv.h"
#include "sql_update.h"
#include "sql_cache.h" // query_cache_*
#include "sql_base.h" // close_tables_for_reopen
#include "sql_parse.h" // cleanup_items
#include "sql_partition.h" // partition_key_modified
#include "sql_select.h"
#include "sql_view.h" // check_key_in_view
#include "sp_head.h"
#include "sql_trigger.h"
#include "sql_statistics.h"
#include "probes_mysql.h"
#include "debug_sync.h"
#include "key.h" // is_key_used
#include "records.h" // init_read_record,
// end_read_record
#include "filesort.h" // filesort
#include "sql_derived.h" // mysql_derived_prepare,
// mysql_handle_derived,
// mysql_derived_filling
#include "sql_insert.h" // For vers_insert_history_row() that may be
// needed for System Versioning.
/**
True if the table's input and output record buffers are comparable using
compare_record(TABLE*).
*/
bool records_are_comparable(const TABLE *table) {
return !table->versioned(VERS_TRX_ID) &&
(((table->file->ha_table_flags() & HA_PARTIAL_COLUMN_READ) == 0) ||
bitmap_is_subset(table->write_set, table->read_set));
}
/**
Compares the input and outbut record buffers of the table to see if a row
has changed.
@return true if row has changed.
@return false otherwise.
*/
bool compare_record(const TABLE *table)
{
DBUG_ASSERT(records_are_comparable(table));
if (table->file->ha_table_flags() & HA_PARTIAL_COLUMN_READ ||
table->s->has_update_default_function)
{
/*
Storage engine may not have read all columns of the record. Fields
(including NULL bits) not in the write_set may not have been read and
can therefore not be compared.
Or ON UPDATE DEFAULT NOW() could've changed field values, including
NULL bits.
*/
for (Field **ptr= table->field ; *ptr != NULL; ptr++)
{
Field *field= *ptr;
if (field->has_explicit_value() && !field->vcol_info)
{
if (field->real_maybe_null())
{
uchar null_byte_index= (uchar)(field->null_ptr - table->record[0]);
if (((table->record[0][null_byte_index]) & field->null_bit) !=
((table->record[1][null_byte_index]) & field->null_bit))
return TRUE;
}
if (field->cmp_binary_offset(table->s->rec_buff_length))
return TRUE;
}
}
return FALSE;
}
/*
The storage engine has read all columns, so it's safe to compare all bits
including those not in the write_set. This is cheaper than the
field-by-field comparison done above.
*/
if (table->s->can_cmp_whole_record)
return cmp_record(table,record[1]);
/* Compare null bits */
if (memcmp(table->null_flags,
table->null_flags+table->s->rec_buff_length,
table->s->null_bytes_for_compare))
return TRUE; // Diff in NULL value
/* Compare updated fields */
for (Field **ptr= table->field ; *ptr ; ptr++)
{
Field *field= *ptr;
if (field->has_explicit_value() && !field->vcol_info &&
field->cmp_binary_offset(table->s->rec_buff_length))
return TRUE;
}
return FALSE;
}
/*
check that all fields are real fields
SYNOPSIS
check_fields()
thd thread handler
items Items for check
RETURN
TRUE Items can't be used in UPDATE
FALSE Items are OK
*/
static bool check_fields(THD *thd, TABLE_LIST *table, List<Item> &items,
bool update_view)
{
Item *item;
if (update_view)
{
List_iterator<Item> it(items);
Item_field *field;
while ((item= it++))
{
if (!(field= item->field_for_view_update()))
{
/* item has name, because it comes from VIEW SELECT list */
my_error(ER_NONUPDATEABLE_COLUMN, MYF(0), item->name.str);
return TRUE;
}
/*
we make temporary copy of Item_field, to avoid influence of changing
result_field on Item_ref which refer on this field
*/
thd->change_item_tree(it.ref(),
new (thd->mem_root) Item_field(thd, field));
}
}
if (thd->variables.sql_mode & MODE_SIMULTANEOUS_ASSIGNMENT)
{
// Make sure that a column is updated only once
List_iterator_fast<Item> it(items);
while ((item= it++))
{
item->field_for_view_update()->field->clear_has_explicit_value();
}
it.rewind();
while ((item= it++))
{
Field *f= item->field_for_view_update()->field;
if (f->has_explicit_value())
{
my_error(ER_UPDATED_COLUMN_ONLY_ONCE, MYF(0),
*(f->table_name), f->field_name.str);
return TRUE;
}
f->set_has_explicit_value();
}
}
if (table->has_period())
{
if (table->is_view_or_derived())
{
my_error(ER_IT_IS_A_VIEW, MYF(0), table->table_name.str);
return TRUE;
}
if (thd->lex->sql_command == SQLCOM_UPDATE_MULTI)
{
my_error(ER_NOT_SUPPORTED_YET, MYF(0),
"updating and querying the same temporal periods table");
return true;
}
DBUG_ASSERT(thd->lex->sql_command == SQLCOM_UPDATE);
for (List_iterator_fast<Item> it(items); (item=it++);)
{
Field *f= item->field_for_view_update()->field;
vers_select_conds_t &period= table->period_conditions;
if (period.field_start->field == f || period.field_end->field == f)
{
my_error(ER_PERIOD_COLUMNS_UPDATED, MYF(0),
item->name.str, period.name.str);
return true;
}
}
}
return FALSE;
}
bool TABLE::vers_check_update(List<Item> &items)
{
List_iterator<Item> it(items);
if (!versioned_write())
return false;
while (Item *item= it++)
{
if (Item_field *item_field= item->field_for_view_update())
{
Field *field= item_field->field;
if (field->table == this && !field->vers_update_unversioned())
{
no_cache= true;
return true;
}
}
}
/*
Tell TRX_ID-versioning that it does not insert history row
(see calc_row_difference()).
*/
vers_write= false;
return false;
}
/**
Re-read record if more columns are needed for error message.
If we got a duplicate key error, we want to write an error
message containing the value of the duplicate key. If we do not have
all fields of the key value in record[0], we need to re-read the
record with a proper read_set.
@param[in] error error number
@param[in] table table
*/
static void prepare_record_for_error_message(int error, TABLE *table)
{
Field **field_p;
Field *field;
uint keynr;
MY_BITMAP unique_map; /* Fields in offended unique. */
my_bitmap_map unique_map_buf[bitmap_buffer_size(MAX_FIELDS)];
DBUG_ENTER("prepare_record_for_error_message");
/*
Only duplicate key errors print the key value.
If storage engine does always read all columns, we have the value alraedy.
*/
if ((error != HA_ERR_FOUND_DUPP_KEY) ||
!(table->file->ha_table_flags() & HA_PARTIAL_COLUMN_READ))
DBUG_VOID_RETURN;
/*
Get the number of the offended index.
We will see MAX_KEY if the engine cannot determine the affected index.
*/
if (unlikely((keynr= table->file->get_dup_key(error)) >= MAX_KEY))
DBUG_VOID_RETURN;
/* Create unique_map with all fields used by that index. */
my_bitmap_init(&unique_map, unique_map_buf, table->s->fields, FALSE);
table->mark_index_columns(keynr, &unique_map);
/* Subtract read_set and write_set. */
bitmap_subtract(&unique_map, table->read_set);
bitmap_subtract(&unique_map, table->write_set);
/*
If the unique index uses columns that are neither in read_set
nor in write_set, we must re-read the record.
Otherwise no need to do anything.
*/
if (bitmap_is_clear_all(&unique_map))
DBUG_VOID_RETURN;
/* Get identifier of last read record into table->file->ref. */
table->file->position(table->record[0]);
/* Add all fields used by unique index to read_set. */
bitmap_union(table->read_set, &unique_map);
/* Tell the engine about the new set. */
table->file->column_bitmaps_signal();
if ((error= table->file->ha_index_or_rnd_end()) ||
(error= table->file->ha_rnd_init(0)))
{
table->file->print_error(error, MYF(0));
DBUG_VOID_RETURN;
}
/* Read record that is identified by table->file->ref. */
(void) table->file->ha_rnd_pos(table->record[1], table->file->ref);
/* Copy the newly read columns into the new record. */
for (field_p= table->field; (field= *field_p); field_p++)
if (bitmap_is_set(&unique_map, field->field_index))
field->copy_from_tmp(table->s->rec_buff_length);
DBUG_VOID_RETURN;
}
static
int cut_fields_for_portion_of_time(THD *thd, TABLE *table,
const vers_select_conds_t &period_conds)
{
bool lcond= period_conds.field_start->val_datetime_packed(thd)
< period_conds.start.item->val_datetime_packed(thd);
bool rcond= period_conds.field_end->val_datetime_packed(thd)
> period_conds.end.item->val_datetime_packed(thd);
Field *start_field= table->field[table->s->period.start_fieldno];
Field *end_field= table->field[table->s->period.end_fieldno];
int res= 0;
if (lcond)
{
res= period_conds.start.item->save_in_field(start_field, true);
start_field->set_has_explicit_value();
}
if (likely(!res) && rcond)
{
res= period_conds.end.item->save_in_field(end_field, true);
end_field->set_has_explicit_value();
}
return res;
}
/*
Process usual UPDATE
SYNOPSIS
mysql_update()
thd thread handler
fields fields for update
values values of fields for update
conds WHERE clause expression
order_num number of elemen in ORDER BY clause
order ORDER BY clause list
limit limit clause
RETURN
0 - OK
2 - privilege check and openning table passed, but we need to convert to
multi-update because of view substitution
1 - error
*/
int mysql_update(THD *thd,
TABLE_LIST *table_list,
List<Item> &fields,
List<Item> &values,
COND *conds,
uint order_num, ORDER *order,
ha_rows limit,
bool ignore,
ha_rows *found_return, ha_rows *updated_return)
{
bool using_limit= limit != HA_POS_ERROR;
bool safe_update= (thd->variables.option_bits & OPTION_SAFE_UPDATES)
&& !thd->lex->describe;
bool used_key_is_modified= FALSE, transactional_table;
bool will_batch= FALSE;
bool can_compare_record;
int res;
int error, loc_error;
ha_rows dup_key_found;
bool need_sort= TRUE;
bool reverse= FALSE;
#ifndef NO_EMBEDDED_ACCESS_CHECKS
privilege_t want_privilege(NO_ACL);
#endif
uint table_count= 0;
ha_rows updated, found;
key_map old_covering_keys;
TABLE *table;
SQL_SELECT *select= NULL;
SORT_INFO *file_sort= 0;
READ_RECORD info;
SELECT_LEX *select_lex= thd->lex->first_select_lex();
ulonglong id;
List<Item> all_fields;
killed_state killed_status= NOT_KILLED;
bool has_triggers, binlog_is_row, do_direct_update= FALSE;
Update_plan query_plan(thd->mem_root);
Explain_update *explain;
TABLE_LIST *update_source_table;
query_plan.index= MAX_KEY;
query_plan.using_filesort= FALSE;
// For System Versioning (may need to insert new fields to a table).
ha_rows rows_inserted= 0;
DBUG_ENTER("mysql_update");
create_explain_query(thd->lex, thd->mem_root);
if (open_tables(thd, &table_list, &table_count, 0))
DBUG_RETURN(1);
/* Prepare views so they are handled correctly */
if (mysql_handle_derived(thd->lex, DT_INIT))
DBUG_RETURN(1);
if (table_list->has_period() && table_list->is_view_or_derived())
{
my_error(ER_IT_IS_A_VIEW, MYF(0), table_list->table_name.str);
DBUG_RETURN(TRUE);
}
if (((update_source_table=unique_table(thd, table_list,
table_list->next_global, 0)) ||
table_list->is_multitable()))
{
DBUG_ASSERT(update_source_table || table_list->view != 0);
DBUG_PRINT("info", ("Switch to multi-update"));
/* pass counter value */
thd->lex->table_count_update= table_count;
if (thd->lex->period_conditions.is_set())
{
my_error(ER_NOT_SUPPORTED_YET, MYF(0),
"updating and querying the same temporal periods table");
DBUG_RETURN(1);
}
/* convert to multiupdate */
DBUG_RETURN(2);
}
if (lock_tables(thd, table_list, table_count, 0))
DBUG_RETURN(1);
(void) read_statistics_for_tables_if_needed(thd, table_list);
THD_STAGE_INFO(thd, stage_init_update);
if (table_list->handle_derived(thd->lex, DT_MERGE_FOR_INSERT))
DBUG_RETURN(1);
if (table_list->handle_derived(thd->lex, DT_PREPARE))
DBUG_RETURN(1);
table= table_list->table;
if (!table_list->single_table_updatable())
{
my_error(ER_NON_UPDATABLE_TABLE, MYF(0), table_list->alias.str, "UPDATE");
DBUG_RETURN(1);
}
/* Calculate "table->covering_keys" based on the WHERE */
table->covering_keys= table->s->keys_in_use;
table->opt_range_keys.clear_all();
query_plan.select_lex= thd->lex->first_select_lex();
query_plan.table= table;
#ifndef NO_EMBEDDED_ACCESS_CHECKS
/* Force privilege re-checking for views after they have been opened. */
want_privilege= (table_list->view ? UPDATE_ACL :
table_list->grant.want_privilege);
#endif
promote_select_describe_flag_if_needed(thd->lex);
if (mysql_prepare_update(thd, table_list, &conds, order_num, order))
DBUG_RETURN(1);
if (table_list->has_period())
{
if (!table_list->period_conditions.start.item->const_item()
|| !table_list->period_conditions.end.item->const_item())
{
my_error(ER_NOT_CONSTANT_EXPRESSION, MYF(0), "FOR PORTION OF");
DBUG_RETURN(true);
}
table->no_cache= true;
}
old_covering_keys= table->covering_keys; // Keys used in WHERE
/* Check the fields we are going to modify */
#ifndef NO_EMBEDDED_ACCESS_CHECKS
table_list->grant.want_privilege= table->grant.want_privilege= want_privilege;
table_list->register_want_access(want_privilege);
#endif
/* 'Unfix' fields to allow correct marking by the setup_fields function. */
if (table_list->is_view())
unfix_fields(fields);
if (setup_fields_with_no_wrap(thd, Ref_ptr_array(),
fields, MARK_COLUMNS_WRITE, 0, 0))
DBUG_RETURN(1); /* purecov: inspected */
if (check_fields(thd, table_list, fields, table_list->view))
{
DBUG_RETURN(1);
}
bool has_vers_fields= table->vers_check_update(fields);
if (check_key_in_view(thd, table_list))
{
my_error(ER_NON_UPDATABLE_TABLE, MYF(0), table_list->alias.str, "UPDATE");
DBUG_RETURN(1);
}
if (table->default_field)
table->mark_default_fields_for_write(false);
#ifndef NO_EMBEDDED_ACCESS_CHECKS
/* Check values */
table_list->grant.want_privilege= table->grant.want_privilege=
(SELECT_ACL & ~table->grant.privilege);
#endif
if (setup_fields(thd, Ref_ptr_array(), values, MARK_COLUMNS_READ, 0, NULL, 0))
{
free_underlaid_joins(thd, select_lex);
DBUG_RETURN(1); /* purecov: inspected */
}
if (check_unique_table(thd, table_list))
DBUG_RETURN(TRUE);
switch_to_nullable_trigger_fields(fields, table);
switch_to_nullable_trigger_fields(values, table);
/* Apply the IN=>EXISTS transformation to all subqueries and optimize them */
if (select_lex->optimize_unflattened_subqueries(false))
DBUG_RETURN(TRUE);
if (select_lex->inner_refs_list.elements &&
fix_inner_refs(thd, all_fields, select_lex, select_lex->ref_pointer_array))
DBUG_RETURN(1);
if (conds)
{
Item::cond_result cond_value;
conds= conds->remove_eq_conds(thd, &cond_value, true);
if (cond_value == Item::COND_FALSE)
{
limit= 0; // Impossible WHERE
query_plan.set_impossible_where();
if (thd->lex->describe || thd->lex->analyze_stmt)
goto produce_explain_and_leave;
}
}
// Don't count on usage of 'only index' when calculating which key to use
table->covering_keys.clear_all();
#ifdef WITH_PARTITION_STORAGE_ENGINE
if (prune_partitions(thd, table, conds))
{
free_underlaid_joins(thd, select_lex);
query_plan.set_no_partitions();
if (thd->lex->describe || thd->lex->analyze_stmt)
goto produce_explain_and_leave;
if (thd->is_error())
DBUG_RETURN(1);
if (!thd->lex->current_select->leaf_tables_saved)
{
thd->lex->current_select->save_leaf_tables(thd);
thd->lex->current_select->leaf_tables_saved= true;
}
my_ok(thd); // No matching records
DBUG_RETURN(0);
}
#endif
/* Update the table->file->stats.records number */
table->file->info(HA_STATUS_VARIABLE | HA_STATUS_NO_LOCK);
set_statistics_for_table(thd, table);
select= make_select(table, 0, 0, conds, (SORT_INFO*) 0, 0, &error);
if (unlikely(error || !limit || thd->is_error() ||
(select && select->check_quick(thd, safe_update, limit))))
{
query_plan.set_impossible_where();
if (thd->lex->describe || thd->lex->analyze_stmt)
goto produce_explain_and_leave;
delete select;
free_underlaid_joins(thd, select_lex);
/*
There was an error or the error was already sent by
the quick select evaluation.
TODO: Add error code output parameter to Item::val_xxx() methods.
Currently they rely on the user checking DA for
errors when unwinding the stack after calling Item::val_xxx().
*/
if (error || thd->is_error())
{
DBUG_RETURN(1); // Error in where
}
if (!thd->lex->current_select->leaf_tables_saved)
{
thd->lex->current_select->save_leaf_tables(thd);
thd->lex->current_select->leaf_tables_saved= true;
}
my_ok(thd); // No matching records
DBUG_RETURN(0);
}
/* If running in safe sql mode, don't allow updates without keys */
if (!select || !select->quick)
{
thd->set_status_no_index_used();
if (safe_update && !using_limit)
{
my_message(ER_UPDATE_WITHOUT_KEY_IN_SAFE_MODE,
ER_THD(thd, ER_UPDATE_WITHOUT_KEY_IN_SAFE_MODE), MYF(0));
goto err;
}
}
if (unlikely(init_ftfuncs(thd, select_lex, 1)))
goto err;
if (table_list->has_period())
{
table->use_all_columns();
table->rpl_write_set= table->write_set;
}
else
{
table->mark_columns_needed_for_update();
}
table->update_const_key_parts(conds);
order= simple_remove_const(order, conds);
query_plan.scanned_rows= select? select->records: table->file->stats.records;
if (select && select->quick && select->quick->unique_key_range())
{
/* Single row select (always "ordered"): Ok to use with key field UPDATE */
need_sort= FALSE;
query_plan.index= MAX_KEY;
used_key_is_modified= FALSE;
}
else
{
ha_rows scanned_limit= query_plan.scanned_rows;
table->no_keyread= 1;
query_plan.index= get_index_for_order(order, table, select, limit,
&scanned_limit, &need_sort,
&reverse);
table->no_keyread= 0;
if (!need_sort)
query_plan.scanned_rows= scanned_limit;
if (select && select->quick)
{
DBUG_ASSERT(need_sort || query_plan.index == select->quick->index);
used_key_is_modified= (!select->quick->unique_key_range() &&
select->quick->is_keys_used(table->write_set));
}
else
{
if (need_sort)
{
/* Assign table scan index to check below for modified key fields: */
query_plan.index= table->file->key_used_on_scan;
}
if (query_plan.index != MAX_KEY)
{
/* Check if we are modifying a key that we are used to search with: */
used_key_is_modified= is_key_used(table, query_plan.index,
table->write_set);
}
}
}
/*
Query optimization is finished at this point.
- Save the decisions in the query plan
- if we're running EXPLAIN UPDATE, get out
*/
query_plan.select= select;
query_plan.possible_keys= select? select->possible_keys: key_map(0);
if (used_key_is_modified || order ||
partition_key_modified(table, table->write_set))
{
if (order && need_sort)
query_plan.using_filesort= true;
else
query_plan.using_io_buffer= true;
}
/*
Ok, we have generated a query plan for the UPDATE.
- if we're running EXPLAIN UPDATE, goto produce explain output
- otherwise, execute the query plan
*/
if (thd->lex->describe)
goto produce_explain_and_leave;
if (!(explain= query_plan.save_explain_update_data(query_plan.mem_root, thd)))
goto err;
ANALYZE_START_TRACKING(thd, &explain->command_tracker);
DBUG_EXECUTE_IF("show_explain_probe_update_exec_start",
dbug_serve_apcs(thd, 1););
has_triggers= (table->triggers &&
(table->triggers->has_triggers(TRG_EVENT_UPDATE,
TRG_ACTION_BEFORE) ||
table->triggers->has_triggers(TRG_EVENT_UPDATE,
TRG_ACTION_AFTER)));
if (table_list->has_period())
has_triggers= table->triggers &&
(table->triggers->has_triggers(TRG_EVENT_INSERT,
TRG_ACTION_BEFORE)
|| table->triggers->has_triggers(TRG_EVENT_INSERT,
TRG_ACTION_AFTER)
|| has_triggers);
DBUG_PRINT("info", ("has_triggers: %s", has_triggers ? "TRUE" : "FALSE"));
binlog_is_row= thd->is_current_stmt_binlog_format_row();
DBUG_PRINT("info", ("binlog_is_row: %s", binlog_is_row ? "TRUE" : "FALSE"));
if (!(select && select->quick))
status_var_increment(thd->status_var.update_scan_count);
/*
We can use direct update (update that is done silently in the handler)
if none of the following conditions are true:
- There are triggers
- There is binary logging
- using_io_buffer
- This means that the partition changed or the key we want
to use for scanning the table is changed
- ignore is set
- Direct updates don't return the number of ignored rows
- There is a virtual not stored column in the WHERE clause
- Changing a field used by a stored virtual column, which
would require the column to be recalculated.
- ORDER BY or LIMIT
- As this requires the rows to be updated in a specific order
- Note that Spider can handle ORDER BY and LIMIT in a cluster with
one data node. These conditions are therefore checked in
direct_update_rows_init().
- Update fields include a unique timestamp field
- The storage engine may not be able to avoid false duplicate key
errors. This condition is checked in direct_update_rows_init().
Direct update does not require a WHERE clause
Later we also ensure that we are only using one table (no sub queries)
*/
DBUG_PRINT("info", ("HA_CAN_DIRECT_UPDATE_AND_DELETE: %s", (table->file->ha_table_flags() & HA_CAN_DIRECT_UPDATE_AND_DELETE) ? "TRUE" : "FALSE"));
DBUG_PRINT("info", ("using_io_buffer: %s", query_plan.using_io_buffer ? "TRUE" : "FALSE"));
DBUG_PRINT("info", ("ignore: %s", ignore ? "TRUE" : "FALSE"));
DBUG_PRINT("info", ("virtual_columns_marked_for_read: %s", table->check_virtual_columns_marked_for_read() ? "TRUE" : "FALSE"));
DBUG_PRINT("info", ("virtual_columns_marked_for_write: %s", table->check_virtual_columns_marked_for_write() ? "TRUE" : "FALSE"));
if ((table->file->ha_table_flags() & HA_CAN_DIRECT_UPDATE_AND_DELETE) &&
!has_triggers && !binlog_is_row &&
!query_plan.using_io_buffer && !ignore &&
!table->check_virtual_columns_marked_for_read() &&
!table->check_virtual_columns_marked_for_write())
{
DBUG_PRINT("info", ("Trying direct update"));
bool use_direct_update= !select || !select->cond;
if (!use_direct_update &&
(select->cond->used_tables() & ~RAND_TABLE_BIT) == table->map)
{
DBUG_ASSERT(!table->file->pushed_cond);
if (!table->file->cond_push(select->cond))
{
use_direct_update= TRUE;
table->file->pushed_cond= select->cond;
}
}
if (use_direct_update &&
!table->file->info_push(INFO_KIND_UPDATE_FIELDS, &fields) &&
!table->file->info_push(INFO_KIND_UPDATE_VALUES, &values) &&
!table->file->direct_update_rows_init(&fields))
{
do_direct_update= TRUE;
/* Direct update is not using_filesort and is not using_io_buffer */
goto update_begin;
}
}
if (query_plan.using_filesort || query_plan.using_io_buffer)
{
/*
We can't update table directly; We must first search after all
matching rows before updating the table!
note: We avoid sorting if we sort on the used index
*/
if (query_plan.using_filesort)
{
/*
Doing an ORDER BY; Let filesort find and sort the rows we are going
to update
NOTE: filesort will call table->prepare_for_position()
*/
Filesort fsort(order, limit, true, select);
Filesort_tracker *fs_tracker=
thd->lex->explain->get_upd_del_plan()->filesort_tracker;
if (!(file_sort= filesort(thd, table, &fsort, fs_tracker)))
goto err;
thd->inc_examined_row_count(file_sort->examined_rows);
/*
Filesort has already found and selected the rows we want to update,
so we don't need the where clause
*/
delete select;
select= 0;
}
else
{
MY_BITMAP *save_read_set= table->read_set;
MY_BITMAP *save_write_set= table->write_set;
if (query_plan.index < MAX_KEY && old_covering_keys.is_set(query_plan.index))
table->prepare_for_keyread(query_plan.index);
else
table->use_all_columns();
/*
We are doing a search on a key that is updated. In this case
we go trough the matching rows, save a pointer to them and
update these in a separate loop based on the pointer.
*/
explain->buf_tracker.on_scan_init();
IO_CACHE tempfile;
if (open_cached_file(&tempfile, mysql_tmpdir,TEMP_PREFIX,
DISK_BUFFER_SIZE, MYF(MY_WME)))
goto err;
/* If quick select is used, initialize it before retrieving rows. */
if (select && select->quick && select->quick->reset())
{
close_cached_file(&tempfile);
goto err;
}
table->file->try_semi_consistent_read(1);
/*
When we get here, we have one of the following options:
A. query_plan.index == MAX_KEY
This means we should use full table scan, and start it with
init_read_record call
B. query_plan.index != MAX_KEY
B.1 quick select is used, start the scan with init_read_record
B.2 quick select is not used, this is full index scan (with LIMIT)
Full index scan must be started with init_read_record_idx
*/
if (query_plan.index == MAX_KEY || (select && select->quick))
error= init_read_record(&info, thd, table, select, NULL, 0, 1, FALSE);
else
error= init_read_record_idx(&info, thd, table, 1, query_plan.index,
reverse);
if (unlikely(error))
{
close_cached_file(&tempfile);
goto err;
}
THD_STAGE_INFO(thd, stage_searching_rows_for_update);
ha_rows tmp_limit= limit;
while (likely(!(error=info.read_record())) && likely(!thd->killed))
{
explain->buf_tracker.on_record_read();
thd->inc_examined_row_count(1);
if (!select || (error= select->skip_record(thd)) > 0)
{
if (table->file->ha_was_semi_consistent_read())
continue; /* repeat the read of the same row if it still exists */
explain->buf_tracker.on_record_after_where();
table->file->position(table->record[0]);
if (unlikely(my_b_write(&tempfile,table->file->ref,
table->file->ref_length)))
{
error=1; /* purecov: inspected */
break; /* purecov: inspected */
}
if (!--limit && using_limit)
{
error= -1;
break;
}
}
else
{
/*
Don't try unlocking the row if skip_record reported an
error since in this case the transaction might have been
rolled back already.
*/
if (unlikely(error < 0))
{
/* Fatal error from select->skip_record() */
error= 1;
break;
}
else
table->file->unlock_row();
}
}
if (unlikely(thd->killed) && !error)
error= 1; // Aborted
limit= tmp_limit;
table->file->try_semi_consistent_read(0);
end_read_record(&info);
/* Change select to use tempfile */
if (select)
{
delete select->quick;
if (select->free_cond)
delete select->cond;
select->quick=0;
select->cond=0;
}
else
{
if (!(select= new SQL_SELECT))
goto err;
select->head=table;
}
if (unlikely(reinit_io_cache(&tempfile,READ_CACHE,0L,0,0)))
error= 1; /* purecov: inspected */
select->file= tempfile; // Read row ptrs from this file
if (unlikely(error >= 0))
goto err;
table->file->ha_end_keyread();
table->column_bitmaps_set(save_read_set, save_write_set);
}
}
update_begin:
if (ignore)
table->file->extra(HA_EXTRA_IGNORE_DUP_KEY);
if (select && select->quick && select->quick->reset())
goto err;
table->file->try_semi_consistent_read(1);
if (init_read_record(&info, thd, table, select, file_sort, 0, 1, FALSE))
goto err;
updated= found= 0;
/*
Generate an error (in TRADITIONAL mode) or warning
when trying to set a NOT NULL field to NULL.
*/
thd->count_cuted_fields= CHECK_FIELD_WARN;
thd->cuted_fields=0L;
transactional_table= table->file->has_transactions_and_rollback();
thd->abort_on_warning= !ignore && thd->is_strict_mode();
if (do_direct_update)
{
/* Direct updating is supported */
ha_rows update_rows= 0, found_rows= 0;
DBUG_PRINT("info", ("Using direct update"));
table->reset_default_fields();
if (unlikely(!(error= table->file->ha_direct_update_rows(&update_rows,
&found_rows))))
error= -1;
updated= update_rows;
found= found_rows;
if (found < updated)
found= updated;
goto update_end;
}
if ((table->file->ha_table_flags() & HA_CAN_FORCE_BULK_UPDATE) &&
!table->prepare_triggers_for_update_stmt_or_event())
will_batch= !table->file->start_bulk_update();
/*
Assure that we can use position()
if we need to create an error message.
*/
if (table->file->ha_table_flags() & HA_PARTIAL_COLUMN_READ)
table->prepare_for_position();
table->reset_default_fields();
/*
We can use compare_record() to optimize away updates if
the table handler is returning all columns OR if
if all updated columns are read
*/
can_compare_record= records_are_comparable(table);
explain->tracker.on_scan_init();
table->file->prepare_for_insert(1);
DBUG_ASSERT(table->file->inited != handler::NONE);
THD_STAGE_INFO(thd, stage_updating);
while (!(error=info.read_record()) && !thd->killed)
{
explain->tracker.on_record_read();
thd->inc_examined_row_count(1);
if (!select || select->skip_record(thd) > 0)
{
if (table->file->ha_was_semi_consistent_read())
continue; /* repeat the read of the same row if it still exists */
explain->tracker.on_record_after_where();
store_record(table,record[1]);
if (table_list->has_period())
cut_fields_for_portion_of_time(thd, table,
table_list->period_conditions);
if (fill_record_n_invoke_before_triggers(thd, table, fields, values, 0,
TRG_EVENT_UPDATE))
break; /* purecov: inspected */
found++;
bool record_was_same= false;
bool need_update= !can_compare_record || compare_record(table);
if (need_update)
{
if (table->versioned(VERS_TIMESTAMP) &&
thd->lex->sql_command == SQLCOM_DELETE)
table->vers_update_end();
if ((res= table_list->view_check_option(thd, ignore)) !=
VIEW_CHECK_OK)
{
found--;
if (res == VIEW_CHECK_SKIP)
continue;
else if (res == VIEW_CHECK_ERROR)
{
error= 1;
break;
}
}
if (will_batch)
{
/*
Typically a batched handler can execute the batched jobs when:
1) When specifically told to do so
2) When it is not a good idea to batch anymore
3) When it is necessary to send batch for other reasons
(One such reason is when READ's must be performed)
1) is covered by exec_bulk_update calls.
2) and 3) is handled by the bulk_update_row method.
bulk_update_row can execute the updates including the one
defined in the bulk_update_row or not including the row
in the call. This is up to the handler implementation and can
vary from call to call.
The dup_key_found reports the number of duplicate keys found
in those updates actually executed. It only reports those if
the extra call with HA_EXTRA_IGNORE_DUP_KEY have been issued.
If this hasn't been issued it returns an error code and can
ignore this number. Thus any handler that implements batching
for UPDATE IGNORE must also handle this extra call properly.
If a duplicate key is found on the record included in this
call then it should be included in the count of dup_key_found
and error should be set to 0 (only if these errors are ignored).
*/
DBUG_PRINT("info", ("Batched update"));
error= table->file->ha_bulk_update_row(table->record[1],
table->record[0],
&dup_key_found);
limit+= dup_key_found;
updated-= dup_key_found;
}
else
{
/* Non-batched update */
error= table->file->ha_update_row(table->record[1],
table->record[0]);
}
record_was_same= error == HA_ERR_RECORD_IS_THE_SAME;
if (unlikely(record_was_same))
{
error= 0;
}
else if (likely(!error))
{
if (has_vers_fields && table->versioned(VERS_TRX_ID))
rows_inserted++;
updated++;
}
if (likely(!error) && !record_was_same && table_list->has_period())
{
store_record(table, record[2]);
restore_record(table, record[1]);
error= table->insert_portion_of_time(thd,
table_list->period_conditions,
&rows_inserted);
restore_record(table, record[2]);
}
if (unlikely(error) &&
(!ignore || table->file->is_fatal_error(error, HA_CHECK_ALL)))
{
goto error;
}
}
if (likely(!error) && has_vers_fields && table->versioned(VERS_TIMESTAMP))
{
store_record(table, record[2]);
table->mark_columns_per_binlog_row_image();
error= vers_insert_history_row(table);
restore_record(table, record[2]);
if (unlikely(error))
{
error:
/*
If (ignore && error is ignorable) we don't have to
do anything; otherwise...
*/
myf flags= 0;
if (table->file->is_fatal_error(error, HA_CHECK_ALL))
flags|= ME_FATAL; /* Other handler errors are fatal */
prepare_record_for_error_message(error, table);
table->file->print_error(error,MYF(flags));
error= 1;
break;
}
rows_inserted++;
}
void *save_bulk_param= thd->bulk_param;
thd->bulk_param= nullptr;
if (table->triggers &&
unlikely(table->triggers->process_triggers(thd, TRG_EVENT_UPDATE,
TRG_ACTION_AFTER, TRUE)))
{
error= 1;
thd->bulk_param= save_bulk_param;
break;
}
thd->bulk_param= save_bulk_param;
if (!--limit && using_limit)
{
/*
We have reached end-of-file in most common situations where no
batching has occurred and if batching was supposed to occur but
no updates were made and finally when the batch execution was
performed without error and without finding any duplicate keys.
If the batched updates were performed with errors we need to
check and if no error but duplicate key's found we need to
continue since those are not counted for in limit.
*/
if (will_batch &&
((error= table->file->exec_bulk_update(&dup_key_found)) ||
dup_key_found))
{
if (error)
{
/* purecov: begin inspected */
/*
The handler should not report error of duplicate keys if they
are ignored. This is a requirement on batching handlers.
*/
prepare_record_for_error_message(error, table);
table->file->print_error(error,MYF(0));
error= 1;
break;
/* purecov: end */
}
/*
Either an error was found and we are ignoring errors or there
were duplicate keys found. In both cases we need to correct
the counters and continue the loop.
*/
limit= dup_key_found; //limit is 0 when we get here so need to +
updated-= dup_key_found;
}
else
{
error= -1; // Simulate end of file
break;
}
}
}
/*
Don't try unlocking the row if skip_record reported an error since in
this case the transaction might have been rolled back already.
*/
else if (likely(!thd->is_error()))
table->file->unlock_row();
else
{
error= 1;
break;
}
thd->get_stmt_da()->inc_current_row_for_warning();
if (unlikely(thd->is_error()))
{
error= 1;
break;
}
}
ANALYZE_STOP_TRACKING(thd, &explain->command_tracker);
table->auto_increment_field_not_null= FALSE;
dup_key_found= 0;
/*
Caching the killed status to pass as the arg to query event constuctor;
The cached value can not change whereas the killed status can
(externally) since this point and change of the latter won't affect
binlogging.
It's assumed that if an error was set in combination with an effective
killed status then the error is due to killing.
*/
killed_status= thd->killed; // get the status of the volatile
// simulated killing after the loop must be ineffective for binlogging
DBUG_EXECUTE_IF("simulate_kill_bug27571",
{
thd->set_killed(KILL_QUERY);
};);
error= (killed_status == NOT_KILLED)? error : 1;
if (likely(error) &&
will_batch &&
(loc_error= table->file->exec_bulk_update(&dup_key_found)))
/*
An error has occurred when a batched update was performed and returned
an error indication. It cannot be an allowed duplicate key error since
we require the batching handler to treat this as a normal behavior.
Otherwise we simply remove the number of duplicate keys records found
in the batched update.
*/
{
/* purecov: begin inspected */
prepare_record_for_error_message(loc_error, table);
table->file->print_error(loc_error,MYF(ME_FATAL));
error= 1;
/* purecov: end */
}
else
updated-= dup_key_found;
if (will_batch)
table->file->end_bulk_update();
update_end:
table->file->try_semi_consistent_read(0);
if (!transactional_table && updated > 0)
thd->transaction->stmt.modified_non_trans_table= TRUE;
end_read_record(&info);
delete select;
select= NULL;
THD_STAGE_INFO(thd, stage_end);
if (table_list->has_period())
table->file->ha_release_auto_increment();
(void) table->file->extra(HA_EXTRA_NO_IGNORE_DUP_KEY);
/*
Invalidate the table in the query cache if something changed.
This must be before binlog writing and ha_autocommit_...
*/
if (updated)
{
query_cache_invalidate3(thd, table_list, 1);
}
if (thd->transaction->stmt.modified_non_trans_table)
thd->transaction->all.modified_non_trans_table= TRUE;
thd->transaction->all.m_unsafe_rollback_flags|=
(thd->transaction->stmt.m_unsafe_rollback_flags & THD_TRANS::DID_WAIT);
/*
error < 0 means really no error at all: we processed all rows until the
last one without error. error > 0 means an error (e.g. unique key
violation and no IGNORE or REPLACE). error == 0 is also an error (if
preparing the record or invoking before triggers fails). See
ha_autocommit_or_rollback(error>=0) and DBUG_RETURN(error>=0) below.
Sometimes we want to binlog even if we updated no rows, in case user used
it to be sure master and slave are in same state.
*/
if (likely(error < 0) || thd->transaction->stmt.modified_non_trans_table)
{
if (WSREP_EMULATE_BINLOG(thd) || mysql_bin_log.is_open())
{
int errcode= 0;
if (likely(error < 0))
thd->clear_error();
else
errcode= query_error_code(thd, killed_status == NOT_KILLED);
ScopedStatementReplication scoped_stmt_rpl(
table->versioned(VERS_TRX_ID) ? thd : NULL);
if (thd->binlog_query(THD::ROW_QUERY_TYPE,
thd->query(), thd->query_length(),
transactional_table, FALSE, FALSE, errcode) > 0)
{
error=1; // Rollback update
}
}
}
DBUG_ASSERT(transactional_table || !updated || thd->transaction->stmt.modified_non_trans_table);
free_underlaid_joins(thd, select_lex);
delete file_sort;
if (table->file->pushed_cond)
{
table->file->pushed_cond= 0;
table->file->cond_pop();
}
/* If LAST_INSERT_ID(X) was used, report X */
id= thd->arg_of_last_insert_id_function ?
thd->first_successful_insert_id_in_prev_stmt : 0;
if (likely(error < 0) && likely(!thd->lex->analyze_stmt))
{
char buff[MYSQL_ERRMSG_SIZE];
if (!table->versioned(VERS_TIMESTAMP) && !table_list->has_period())
my_snprintf(buff, sizeof(buff), ER_THD(thd, ER_UPDATE_INFO), (ulong) found,
(ulong) updated,
(ulong) thd->get_stmt_da()->current_statement_warn_count());
else
my_snprintf(buff, sizeof(buff),
ER_THD(thd, ER_UPDATE_INFO_WITH_SYSTEM_VERSIONING),
(ulong) found, (ulong) updated, (ulong) rows_inserted,
(ulong) thd->get_stmt_da()->current_statement_warn_count());
my_ok(thd, (thd->client_capabilities & CLIENT_FOUND_ROWS) ? found : updated,
id, buff);
if (thd->get_stmt_da()->is_bulk_op())
{
/*
Update the diagnostics message sent to a client with number of actual
rows update by the statement. For bulk UPDATE operation it should be
done after returning from my_ok() since the final number of updated
rows be knows on finishing the entire bulk update statement.
*/
my_snprintf(buff, sizeof(buff), ER_THD(thd, ER_UPDATE_INFO),
(ulong) thd->get_stmt_da()->affected_rows(),
(ulong) thd->get_stmt_da()->affected_rows(),
(ulong) thd->get_stmt_da()->current_statement_warn_count());
thd->get_stmt_da()->set_message(buff);
}
DBUG_PRINT("info",("%ld records updated", (long) updated));
}
thd->count_cuted_fields= CHECK_FIELD_IGNORE; /* calc cuted fields */
thd->abort_on_warning= 0;
if (!thd->lex->current_select->leaf_tables_saved)
{
thd->lex->current_select->save_leaf_tables(thd);
thd->lex->current_select->leaf_tables_saved= true;
}
*found_return= found;
*updated_return= updated;
if (unlikely(thd->lex->analyze_stmt))
goto emit_explain_and_leave;
DBUG_RETURN((error >= 0 || thd->is_error()) ? 1 : 0);
err:
delete select;
delete file_sort;
free_underlaid_joins(thd, select_lex);
table->file->ha_end_keyread();
if (table->file->pushed_cond)
table->file->cond_pop();
thd->abort_on_warning= 0;
DBUG_RETURN(1);
produce_explain_and_leave:
/*
We come here for various "degenerate" query plans: impossible WHERE,
no-partitions-used, impossible-range, etc.
*/
if (unlikely(!query_plan.save_explain_update_data(query_plan.mem_root, thd)))
goto err;
emit_explain_and_leave:
bool extended= thd->lex->describe & DESCRIBE_EXTENDED;
int err2= thd->lex->explain->send_explain(thd, extended);
delete select;
free_underlaid_joins(thd, select_lex);
DBUG_RETURN((err2 || thd->is_error()) ? 1 : 0);
}
/*
Prepare items in UPDATE statement
SYNOPSIS
mysql_prepare_update()
thd - thread handler
table_list - global/local table list
conds - conditions
order_num - number of ORDER BY list entries
order - ORDER BY clause list
RETURN VALUE
FALSE OK
TRUE error
*/
bool mysql_prepare_update(THD *thd, TABLE_LIST *table_list,
Item **conds, uint order_num, ORDER *order)
{
Item *fake_conds= 0;
#ifndef NO_EMBEDDED_ACCESS_CHECKS
TABLE *table= table_list->table;
#endif
List<Item> all_fields;
SELECT_LEX *select_lex= thd->lex->first_select_lex();
DBUG_ENTER("mysql_prepare_update");
#ifndef NO_EMBEDDED_ACCESS_CHECKS
table_list->grant.want_privilege= table->grant.want_privilege=
(SELECT_ACL & ~table->grant.privilege);
table_list->register_want_access(SELECT_ACL);
#endif
thd->lex->allow_sum_func.clear_all();
if (table_list->has_period() &&
select_lex->period_setup_conds(thd, table_list))
DBUG_RETURN(true);
DBUG_ASSERT(table_list->table);
// conds could be cached from previous SP call
DBUG_ASSERT(!table_list->vers_conditions.need_setup() ||
!*conds || thd->stmt_arena->is_stmt_execute());
if (select_lex->vers_setup_conds(thd, table_list))
DBUG_RETURN(TRUE);
*conds= select_lex->where;
/*
We do not call DT_MERGE_FOR_INSERT because it has no sense for simple
(not multi-) update
*/
if (mysql_handle_derived(thd->lex, DT_PREPARE))
DBUG_RETURN(TRUE);
if (setup_tables_and_check_access(thd, &select_lex->context,
&select_lex->top_join_list, table_list,
select_lex->leaf_tables,
FALSE, UPDATE_ACL, SELECT_ACL, TRUE) ||
setup_conds(thd, table_list, select_lex->leaf_tables, conds) ||
select_lex->setup_ref_array(thd, order_num) ||
setup_order(thd, select_lex->ref_pointer_array,
table_list, all_fields, all_fields, order) ||
setup_ftfuncs(select_lex))
DBUG_RETURN(TRUE);
select_lex->fix_prepare_information(thd, conds, &fake_conds);
if (!thd->lex->upd_del_where)
thd->lex->upd_del_where= *conds;
DBUG_RETURN(FALSE);
}
/**
Check that we are not using table that we are updating in a sub select
@param thd Thread handle
@param table_list List of table with first to check
@retval TRUE Error
@retval FALSE OK
*/
bool check_unique_table(THD *thd, TABLE_LIST *table_list)
{
TABLE_LIST *duplicate;
DBUG_ENTER("check_unique_table");
if ((duplicate= unique_table(thd, table_list, table_list->next_global, 0)))
{
update_non_unique_table_error(table_list, "UPDATE", duplicate);
DBUG_RETURN(TRUE);
}
DBUG_RETURN(FALSE);
}
/***************************************************************************
Update multiple tables from join
***************************************************************************/
/*
Get table map for list of Item_field
*/
static table_map get_table_map(List<Item> *items)
{
List_iterator_fast<Item> item_it(*items);
Item_field *item;
table_map map= 0;
while ((item= (Item_field *) item_it++))
map|= item->all_used_tables();
DBUG_PRINT("info", ("table_map: 0x%08lx", (long) map));
return map;
}
/**
If one row is updated through two different aliases and the first
update physically moves the row, the second update will error
because the row is no longer located where expected. This function
checks if the multiple-table update is about to do that and if so
returns with an error.
The following update operations physically moves rows:
1) Update of a column in a clustered primary key
2) Update of a column used to calculate which partition the row belongs to
This function returns with an error if both of the following are
true:
a) A table in the multiple-table update statement is updated
through multiple aliases (including views)
b) At least one of the updates on the table from a) may physically
moves the row. Note: Updating a column used to calculate which
partition a row belongs to does not necessarily mean that the
row is moved. The new value may or may not belong to the same
partition.
@param leaves First leaf table
@param tables_for_update Map of tables that are updated
@return
true if the update is unsafe, in which case an error message is also set,
false otherwise.
*/
static
bool unsafe_key_update(List<TABLE_LIST> leaves, table_map tables_for_update)
{
List_iterator_fast<TABLE_LIST> it(leaves), it2(leaves);
TABLE_LIST *tl, *tl2;
while ((tl= it++))
{
if (!tl->is_jtbm() && (tl->table->map & tables_for_update))
{
TABLE *table1= tl->table;
bool primkey_clustered= (table1->file->
pk_is_clustering_key(table1->s->primary_key));
bool table_partitioned= false;
#ifdef WITH_PARTITION_STORAGE_ENGINE
table_partitioned= (table1->part_info != NULL);
#endif
if (!table_partitioned && !primkey_clustered)
continue;
it2.rewind();
while ((tl2= it2++))
{
if (tl2->is_jtbm())
continue;
/*
Look at "next" tables only since all previous tables have
already been checked
*/
TABLE *table2= tl2->table;
if (tl2 != tl &&
table2->map & tables_for_update && table1->s == table2->s)
{
// A table is updated through two aliases
if (table_partitioned &&
(partition_key_modified(table1, table1->write_set) ||
partition_key_modified(table2, table2->write_set)))
{
// Partitioned key is updated
my_error(ER_MULTI_UPDATE_KEY_CONFLICT, MYF(0),
tl->top_table()->alias.str,
tl2->top_table()->alias.str);
return true;
}
if (primkey_clustered)
{
// The primary key can cover multiple columns
KEY key_info= table1->key_info[table1->s->primary_key];
KEY_PART_INFO *key_part= key_info.key_part;
KEY_PART_INFO *key_part_end= key_part + key_info.user_defined_key_parts;
for (;key_part != key_part_end; ++key_part)
{
if (bitmap_is_set(table1->write_set, key_part->fieldnr-1) ||
bitmap_is_set(table2->write_set, key_part->fieldnr-1))
{
// Clustered primary key is updated
my_error(ER_MULTI_UPDATE_KEY_CONFLICT, MYF(0),
tl->top_table()->alias.str,
tl2->top_table()->alias.str);
return true;
}
}
}
}
}
}
}
return false;
}
/**
Check if there is enough privilege on specific table used by the
main select list of multi-update directly or indirectly (through
a view).
@param[in] thd Thread context.
@param[in] table Table list element for the table.
@param[in] tables_for_update Bitmap with tables being updated.
@param[in/out] updated_arg Set to true if table in question is
updated, also set to true if it is
a view and one of its underlying
tables is updated. Should be
initialized to false by the caller
before a sequence of calls to this
function.
@note To determine which tables/views are updated we have to go from
leaves to root since tables_for_update contains map of leaf
tables being updated and doesn't include non-leaf tables
(fields are already resolved to leaf tables).
@retval false - Success, all necessary privileges on all tables are
present or might be present on column-level.
@retval true - Failure, some necessary privilege on some table is
missing.
*/
static bool multi_update_check_table_access(THD *thd, TABLE_LIST *table,
table_map tables_for_update,
bool *updated_arg)
{
if (table->view)
{
bool updated= false;
/*
If it is a mergeable view then we need to check privileges on its
underlying tables being merged (including views). We also need to
check if any of them is updated in order to find if this view is
updated.
If it is a non-mergeable view then it can't be updated.
*/
DBUG_ASSERT(table->merge_underlying_list ||
(!table->updatable &&
!(table->table->map & tables_for_update)));
for (TABLE_LIST *tbl= table->merge_underlying_list; tbl;
tbl= tbl->next_local)
{
if (multi_update_check_table_access(thd, tbl, tables_for_update,
&updated))
{
tbl->hide_view_error(thd);
return true;
}
}
if (check_table_access(thd, updated ? UPDATE_ACL: SELECT_ACL, table,
FALSE, 1, FALSE))
return true;
*updated_arg|= updated;
/* We only need SELECT privilege for columns in the values list. */
table->grant.want_privilege= SELECT_ACL & ~table->grant.privilege;
}
else
{
/* Must be a base or derived table. */
const bool updated= table->table->map & tables_for_update;
if (check_table_access(thd, updated ? UPDATE_ACL : SELECT_ACL, table,
FALSE, 1, FALSE))
return true;
*updated_arg|= updated;
/* We only need SELECT privilege for columns in the values list. */
if (!table->derived)
{
table->grant.want_privilege= SELECT_ACL & ~table->grant.privilege;
table->table->grant.want_privilege= (SELECT_ACL &
~table->table->grant.privilege);
}
}
return false;
}
class Multiupdate_prelocking_strategy : public DML_prelocking_strategy
{
bool done;
bool has_prelocking_list;
public:
void reset(THD *thd) override;
bool handle_end(THD *thd) override;
};
void Multiupdate_prelocking_strategy::reset(THD *thd)
{
done= false;
has_prelocking_list= thd->lex->requires_prelocking();
}
/**
Determine what tables could be updated in the multi-update
For these tables we'll need to open triggers and continue prelocking
until all is open.
*/
bool Multiupdate_prelocking_strategy::handle_end(THD *thd)
{
DBUG_ENTER("Multiupdate_prelocking_strategy::handle_end");
if (done)
DBUG_RETURN(0);
LEX *lex= thd->lex;
SELECT_LEX *select_lex= lex->first_select_lex();
TABLE_LIST *table_list= lex->query_tables, *tl;
done= true;
if (mysql_handle_derived(lex, DT_INIT) ||
mysql_handle_derived(lex, DT_MERGE_FOR_INSERT) ||
mysql_handle_derived(lex, DT_PREPARE))
DBUG_RETURN(1);
/*
setup_tables() need for VIEWs. JOIN::prepare() will call setup_tables()
second time, but this call will do nothing (there are check for second
call in setup_tables()).
*/
if (setup_tables_and_check_access(thd, &select_lex->context,
&select_lex->top_join_list, table_list, select_lex->leaf_tables,
FALSE, UPDATE_ACL, SELECT_ACL, TRUE))
DBUG_RETURN(1);
List<Item> *fields= &lex->first_select_lex()->item_list;
if (setup_fields_with_no_wrap(thd, Ref_ptr_array(),
*fields, MARK_COLUMNS_WRITE, 0, 0))
DBUG_RETURN(1);
// Check if we have a view in the list ...
for (tl= table_list; tl ; tl= tl->next_local)
if (tl->view)
break;
// ... and pass this knowlage in check_fields call
if (check_fields(thd, table_list, *fields, tl != NULL ))
DBUG_RETURN(1);
table_map tables_for_update= thd->table_map_for_update= get_table_map(fields);
if (unsafe_key_update(select_lex->leaf_tables, tables_for_update))
DBUG_RETURN(1);
/*
Setup timestamp handling and locking mode
*/
List_iterator<TABLE_LIST> ti(lex->first_select_lex()->leaf_tables);
const bool using_lock_tables= thd->locked_tables_mode != LTM_NONE;
while ((tl= ti++))
{
TABLE *table= tl->table;
if (tl->is_jtbm())
continue;
/* if table will be updated then check that it is unique */
if (table->map & tables_for_update)
{
if (!tl->single_table_updatable() || check_key_in_view(thd, tl))
{
my_error(ER_NON_UPDATABLE_TABLE, MYF(0),
tl->top_table()->alias.str, "UPDATE");
DBUG_RETURN(1);
}
DBUG_PRINT("info",("setting table `%s` for update",
tl->top_table()->alias.str));
/*
If table will be updated we should not downgrade lock for it and
leave it as is.
*/
tl->updating= 1;
if (tl->belong_to_view)
tl->belong_to_view->updating= 1;
if (extend_table_list(thd, tl, this, has_prelocking_list))
DBUG_RETURN(1);
}
else
{
DBUG_PRINT("info",("setting table `%s` for read-only", tl->alias.str));
/*
If we are using the binary log, we need TL_READ_NO_INSERT to get
correct order of statements. Otherwise, we use a TL_READ lock to
improve performance.
We don't downgrade metadata lock from SW to SR in this case as
there is no guarantee that the same ticket is not used by
another table instance used by this statement which is going to
be write-locked (for example, trigger to be invoked might try
to update this table).
Last argument routine_modifies_data for read_lock_type_for_table()
is ignored, as prelocking placeholder will never be set here.
*/
DBUG_ASSERT(tl->prelocking_placeholder == false);
thr_lock_type lock_type= read_lock_type_for_table(thd, lex, tl, true);
if (using_lock_tables)
tl->lock_type= lock_type;
else
tl->set_lock_type(thd, lock_type);
}
}
/*
Check access privileges for tables being updated or read.
Note that unlike in the above loop we need to iterate here not only
through all leaf tables but also through all view hierarchy.
*/
for (tl= table_list; tl; tl= tl->next_local)
{
bool not_used= false;
if (tl->is_jtbm())
continue;
if (multi_update_check_table_access(thd, tl, tables_for_update, &not_used))
DBUG_RETURN(TRUE);
}
/* check single table update for view compound from several tables */
for (tl= table_list; tl; tl= tl->next_local)
{
TABLE_LIST *for_update= 0;
if (tl->is_jtbm())
continue;
if (tl->is_merged_derived() &&
tl->check_single_table(&for_update, tables_for_update, tl))
{
my_error(ER_VIEW_MULTIUPDATE, MYF(0), tl->view_db.str, tl->view_name.str);
DBUG_RETURN(1);
}
}
DBUG_RETURN(0);
}
/*
make update specific preparation and checks after opening tables
SYNOPSIS
mysql_multi_update_prepare()
thd thread handler
RETURN
FALSE OK
TRUE Error
*/
int mysql_multi_update_prepare(THD *thd)
{
LEX *lex= thd->lex;
TABLE_LIST *table_list= lex->query_tables;
TABLE_LIST *tl;
Multiupdate_prelocking_strategy prelocking_strategy;
uint table_count= lex->table_count_update;
DBUG_ENTER("mysql_multi_update_prepare");
/*
Open tables and create derived ones, but do not lock and fill them yet.
During prepare phase acquire only S metadata locks instead of SW locks to
keep prepare of multi-UPDATE compatible with concurrent LOCK TABLES WRITE
and global read lock.
Don't evaluate any subqueries even if constant, because
tables aren't locked yet.
*/
lex->context_analysis_only|= CONTEXT_ANALYSIS_ONLY_DERIVED;
if (thd->lex->sql_command == SQLCOM_UPDATE_MULTI)
{
if (open_tables(thd, &table_list, &table_count,
thd->stmt_arena->is_stmt_prepare() ? MYSQL_OPEN_FORCE_SHARED_MDL : 0,
&prelocking_strategy))
DBUG_RETURN(TRUE);
}
else
{
/* following need for prepared statements, to run next time multi-update */
thd->lex->sql_command= SQLCOM_UPDATE_MULTI;
prelocking_strategy.reset(thd);
if (prelocking_strategy.handle_end(thd))
DBUG_RETURN(TRUE);
}
/* now lock and fill tables */
if (!thd->stmt_arena->is_stmt_prepare() &&
lock_tables(thd, table_list, table_count, 0))
DBUG_RETURN(TRUE);
lex->context_analysis_only&= ~CONTEXT_ANALYSIS_ONLY_DERIVED;
(void) read_statistics_for_tables_if_needed(thd, table_list);
/* @todo: downgrade the metadata locks here. */
/*
Check that we are not using table that we are updating, but we should
skip all tables of UPDATE SELECT itself
*/
lex->first_select_lex()->exclude_from_table_unique_test= TRUE;
/* We only need SELECT privilege for columns in the values list */
List_iterator<TABLE_LIST> ti(lex->first_select_lex()->leaf_tables);
while ((tl= ti++))
{
if (tl->is_jtbm())
continue;
TABLE *table= tl->table;
TABLE_LIST *tlist;
if (!(tlist= tl->top_table())->derived)
{
tlist->grant.want_privilege=
(SELECT_ACL & ~tlist->grant.privilege);
table->grant.want_privilege= (SELECT_ACL & ~table->grant.privilege);
}
DBUG_PRINT("info", ("table: %s want_privilege: %llx", tl->alias.str,
(longlong) table->grant.want_privilege));
}
/*
Set exclude_from_table_unique_test value back to FALSE. It is needed for
further check in multi_update::prepare whether to use record cache.
*/
lex->first_select_lex()->exclude_from_table_unique_test= FALSE;
if (lex->save_prep_leaf_tables())
DBUG_RETURN(TRUE);
DBUG_RETURN (FALSE);
}
/*
Setup multi-update handling and call SELECT to do the join
*/
bool mysql_multi_update(THD *thd, TABLE_LIST *table_list, List<Item> *fields,
List<Item> *values, COND *conds, ulonglong options,
enum enum_duplicates handle_duplicates,
bool ignore, SELECT_LEX_UNIT *unit,
SELECT_LEX *select_lex, multi_update **result)
{
bool res;
DBUG_ENTER("mysql_multi_update");
if (!(*result= new (thd->mem_root) multi_update(thd, table_list,
&thd->lex->first_select_lex()->leaf_tables,
fields, values, handle_duplicates, ignore)))
{
DBUG_RETURN(TRUE);
}
if ((*result)->init(thd))
DBUG_RETURN(1);
thd->abort_on_warning= !ignore && thd->is_strict_mode();
List<Item> total_list;
if (setup_tables(thd, &select_lex->context, &select_lex->top_join_list,
table_list, select_lex->leaf_tables, FALSE, FALSE))
DBUG_RETURN(1);
if (select_lex->vers_setup_conds(thd, table_list))
DBUG_RETURN(1);
res= mysql_select(thd,
table_list, total_list, conds,
select_lex->order_list.elements,
select_lex->order_list.first, NULL, NULL, NULL,
options | SELECT_NO_JOIN_CACHE | SELECT_NO_UNLOCK |
OPTION_SETUP_TABLES_DONE,
*result, unit, select_lex);
DBUG_PRINT("info",("res: %d report_error: %d", res, (int) thd->is_error()));
res|= thd->is_error();
if (unlikely(res))
(*result)->abort_result_set();
else
{
if (thd->lex->describe || thd->lex->analyze_stmt)
{
bool extended= thd->lex->describe & DESCRIBE_EXTENDED;
res= thd->lex->explain->send_explain(thd, extended);
}
}
thd->abort_on_warning= 0;
DBUG_RETURN(res);
}
multi_update::multi_update(THD *thd_arg, TABLE_LIST *table_list,
List<TABLE_LIST> *leaves_list,
List<Item> *field_list, List<Item> *value_list,
enum enum_duplicates handle_duplicates_arg,
bool ignore_arg):
select_result_interceptor(thd_arg),
all_tables(table_list), leaves(leaves_list), update_tables(0),
tmp_tables(0), updated(0), found(0), fields(field_list),
values(value_list), table_count(0), copy_field(0),
handle_duplicates(handle_duplicates_arg), do_update(1), trans_safe(1),
transactional_tables(0), ignore(ignore_arg), error_handled(0), prepared(0),
updated_sys_ver(0)
{
}
bool multi_update::init(THD *thd)
{
table_map tables_to_update= get_table_map(fields);
List_iterator_fast<TABLE_LIST> li(*leaves);
TABLE_LIST *tbl;
while ((tbl =li++))
{
if (tbl->is_jtbm())
continue;
if (!(tbl->table->map & tables_to_update))
continue;
if (updated_leaves.push_back(tbl, thd->mem_root))
return true;
}
return false;
}
/*
Connect fields with tables and create list of tables that are updated
*/
int multi_update::prepare(List<Item> &not_used_values,
SELECT_LEX_UNIT *lex_unit)
{
TABLE_LIST *table_ref;
SQL_I_List<TABLE_LIST> update;
table_map tables_to_update;
Item_field *item;
List_iterator_fast<Item> field_it(*fields);
List_iterator_fast<Item> value_it(*values);
uint i, max_fields;
uint leaf_table_count= 0;
List_iterator<TABLE_LIST> ti(updated_leaves);
DBUG_ENTER("multi_update::prepare");
if (prepared)
DBUG_RETURN(0);
prepared= true;
thd->count_cuted_fields= CHECK_FIELD_WARN;
thd->cuted_fields=0L;
THD_STAGE_INFO(thd, stage_updating_main_table);
tables_to_update= get_table_map(fields);
if (!tables_to_update)
{
my_message(ER_NO_TABLES_USED, ER_THD(thd, ER_NO_TABLES_USED), MYF(0));
DBUG_RETURN(1);
}
/*
We gather the set of columns read during evaluation of SET expression in
TABLE::tmp_set by pointing TABLE::read_set to it and then restore it after
setup_fields().
*/
while ((table_ref= ti++))
{
if (table_ref->is_jtbm())
continue;
TABLE *table= table_ref->table;
if (tables_to_update & table->map)
{
DBUG_ASSERT(table->read_set == &table->def_read_set);
table->read_set= &table->tmp_set;
bitmap_clear_all(table->read_set);
}
}
/*
We have to check values after setup_tables to get covering_keys right in
reference tables
*/
int error= setup_fields(thd, Ref_ptr_array(),
*values, MARK_COLUMNS_READ, 0, NULL, 0);
ti.rewind();
while ((table_ref= ti++))
{
if (table_ref->is_jtbm())
continue;
TABLE *table= table_ref->table;
if (tables_to_update & table->map)
{
table->read_set= &table->def_read_set;
bitmap_union(table->read_set, &table->tmp_set);
table->file->prepare_for_insert(1);
}
}
if (unlikely(error))
DBUG_RETURN(1);
/*
Save tables being updated in update_tables
update_table->shared is position for table
Don't use key read on tables that are updated
*/
update.empty();
ti.rewind();
while ((table_ref= ti++))
{
/* TODO: add support of view of join support */
if (table_ref->is_jtbm())
continue;
TABLE *table=table_ref->table;
leaf_table_count++;
if (tables_to_update & table->map)
{
TABLE_LIST *tl= (TABLE_LIST*) thd->memdup(table_ref,
sizeof(*tl));
if (!tl)
DBUG_RETURN(1);
update.link_in_list(tl, &tl->next_local);
table_ref->shared= tl->shared= table_count++;
table->no_keyread=1;
table->covering_keys.clear_all();
table->prepare_triggers_for_update_stmt_or_event();
table->reset_default_fields();
}
}
table_count= update.elements;
update_tables= update.first;
tmp_tables = (TABLE**) thd->calloc(sizeof(TABLE *) * table_count);
tmp_table_param = (TMP_TABLE_PARAM*) thd->calloc(sizeof(TMP_TABLE_PARAM) *
table_count);
fields_for_table= (List_item **) thd->alloc(sizeof(List_item *) *
table_count);
values_for_table= (List_item **) thd->alloc(sizeof(List_item *) *
table_count);
if (unlikely(thd->is_fatal_error))
DBUG_RETURN(1);
for (i=0 ; i < table_count ; i++)
{
fields_for_table[i]= new List_item;
values_for_table[i]= new List_item;
}
if (unlikely(thd->is_fatal_error))
DBUG_RETURN(1);
/* Split fields into fields_for_table[] and values_by_table[] */
while ((item= (Item_field *) field_it++))
{
Item *value= value_it++;
uint offset= item->field->table->pos_in_table_list->shared;
if (value->associate_with_target_field(thd, item))
DBUG_RETURN(1);
fields_for_table[offset]->push_back(item, thd->mem_root);
values_for_table[offset]->push_back(value, thd->mem_root);
}
if (unlikely(thd->is_fatal_error))
DBUG_RETURN(1);
/* Allocate copy fields */
max_fields=0;
for (i=0 ; i < table_count ; i++)
{
set_if_bigger(max_fields, fields_for_table[i]->elements + leaf_table_count);
if (fields_for_table[i]->elements)
{
TABLE *table= ((Item_field*)(fields_for_table[i]->head()))->field->table;
switch_to_nullable_trigger_fields(*fields_for_table[i], table);
switch_to_nullable_trigger_fields(*values_for_table[i], table);
}
}
copy_field= new (thd->mem_root) Copy_field[max_fields];
DBUG_RETURN(thd->is_fatal_error != 0);
}
void multi_update::update_used_tables()
{
Item *item;
List_iterator_fast<Item> it(*values);
while ((item= it++))
{
item->update_used_tables();
}
}
void multi_update::prepare_to_read_rows()
{
/*
update column maps now. it cannot be done in ::prepare() before the
optimizer, because the optimize might reset them (in
SELECT_LEX::update_used_tables()), it cannot be done in
::initialize_tables() after the optimizer, because the optimizer
might read rows from const tables
*/
for (TABLE_LIST *tl= update_tables; tl; tl= tl->next_local)
tl->table->mark_columns_needed_for_update();
}
/*
Check if table is safe to update on fly
SYNOPSIS
safe_update_on_fly()
thd Thread handler
join_tab How table is used in join
all_tables List of tables
NOTES
We can update the first table in join on the fly if we know that
a row in this table will never be read twice. This is true under
the following conditions:
- No column is both written to and read in SET expressions.
- We are doing a table scan and the data is in a separate file (MyISAM) or
if we don't update a clustered key.
- We are doing a range scan and we don't update the scan key or
the primary key for a clustered table handler.
- Table is not joined to itself.
This function gets information about fields to be updated from
the TABLE::write_set bitmap.
WARNING
This code is a bit dependent of how make_join_readinfo() works.
The field table->tmp_set is used for keeping track of which fields are
read during evaluation of the SET expression. See multi_update::prepare.
RETURN
0 Not safe to update
1 Safe to update
*/
static bool safe_update_on_fly(THD *thd, JOIN_TAB *join_tab,
TABLE_LIST *table_ref, TABLE_LIST *all_tables)
{
TABLE *table= join_tab->table;
if (unique_table(thd, table_ref, all_tables, 0))
return 0;
if (join_tab->join->order) // FIXME this is probably too strong
return 0;
switch (join_tab->type) {
case JT_SYSTEM:
case JT_CONST:
case JT_EQ_REF:
return TRUE; // At most one matching row
case JT_REF:
case JT_REF_OR_NULL:
return !is_key_used(table, join_tab->ref.key, table->write_set);
case JT_ALL:
if (bitmap_is_overlapping(&table->tmp_set, table->write_set))
return FALSE;
/* If range search on index */
if (join_tab->quick)
return !join_tab->quick->is_keys_used(table->write_set);
/* If scanning in clustered key */
if ((table->file->ha_table_flags() & HA_PRIMARY_KEY_IN_READ_INDEX) &&
table->s->primary_key < MAX_KEY)
return !is_key_used(table, table->s->primary_key, table->write_set);
return TRUE;
default:
break; // Avoid compiler warning
}
return FALSE;
}
/*
Initialize table for multi table
IMPLEMENTATION
- Update first table in join on the fly, if possible
- Create temporary tables to store changed values for all other tables
that are updated (and main_table if the above doesn't hold).
*/
bool
multi_update::initialize_tables(JOIN *join)
{
TABLE_LIST *table_ref;
DBUG_ENTER("initialize_tables");
if (unlikely((thd->variables.option_bits & OPTION_SAFE_UPDATES) &&
error_if_full_join(join)))
DBUG_RETURN(1);
if (join->implicit_grouping)
{
my_error(ER_INVALID_GROUP_FUNC_USE, MYF(0));
DBUG_RETURN(1);
}
main_table=join->join_tab->table;
table_to_update= 0;
/* Any update has at least one pair (field, value) */
DBUG_ASSERT(fields->elements);
/*
Only one table may be modified by UPDATE of an updatable view.
For an updatable view first_table_for_update indicates this
table.
For a regular multi-update it refers to some updated table.
*/
TABLE *first_table_for_update= ((Item_field *) fields->head())->field->table;
/* Create a temporary table for keys to all tables, except main table */
for (table_ref= update_tables; table_ref; table_ref= table_ref->next_local)
{
TABLE *table=table_ref->table;
uint cnt= table_ref->shared;
List<Item> temp_fields;
ORDER group;
TMP_TABLE_PARAM *tmp_param;
if (ignore)
table->file->extra(HA_EXTRA_IGNORE_DUP_KEY);
if (table == main_table) // First table in join
{
if (safe_update_on_fly(thd, join->join_tab, table_ref, all_tables))
{
table_to_update= table; // Update table on the fly
has_vers_fields= table->vers_check_update(*fields);
continue;
}
}
table->prepare_for_position();
join->map2table[table->tablenr]->keep_current_rowid= true;
/*
enable uncacheable flag if we update a view with check option
and check option has a subselect, otherwise, the check option
can be evaluated after the subselect was freed as independent
(See full_local in JOIN::join_free()).
*/
if (table_ref->check_option && !join->select_lex->uncacheable)
{
SELECT_LEX_UNIT *tmp_unit;
SELECT_LEX *sl;
for (tmp_unit= join->select_lex->first_inner_unit();
tmp_unit;
tmp_unit= tmp_unit->next_unit())
{
for (sl= tmp_unit->first_select(); sl; sl= sl->next_select())
{
if (sl->master_unit()->item)
{
join->select_lex->uncacheable|= UNCACHEABLE_CHECKOPTION;
goto loop_end;
}
}
}
}
loop_end:
if (table == first_table_for_update && table_ref->check_option)
{
table_map unupdated_tables= table_ref->check_option->used_tables() &
~first_table_for_update->map;
List_iterator<TABLE_LIST> ti(*leaves);
TABLE_LIST *tbl_ref;
while ((tbl_ref= ti++) && unupdated_tables)
{
if (unupdated_tables & tbl_ref->table->map)
unupdated_tables&= ~tbl_ref->table->map;
else
continue;
if (unupdated_check_opt_tables.push_back(tbl_ref->table))
DBUG_RETURN(1);
}
}
tmp_param= tmp_table_param+cnt;
/*
Create a temporary table to store all fields that are changed for this
table. The first field in the temporary table is a pointer to the
original row so that we can find and update it. For the updatable
VIEW a few following fields are rowids of tables used in the CHECK
OPTION condition.
*/
List_iterator_fast<TABLE> tbl_it(unupdated_check_opt_tables);
TABLE *tbl= table;
do
{
LEX_CSTRING field_name;
field_name.str= tbl->alias.c_ptr();
field_name.length= strlen(field_name.str);
/*
Signal each table (including tables referenced by WITH CHECK OPTION
clause) for which we will store row position in the temporary table
that we need a position to be read first.
*/
tbl->prepare_for_position();
join->map2table[tbl->tablenr]->keep_current_rowid= true;
Item_temptable_rowid *item=
new (thd->mem_root) Item_temptable_rowid(tbl);
if (!item)
DBUG_RETURN(1);
item->fix_fields(thd, 0);
if (temp_fields.push_back(item, thd->mem_root))
DBUG_RETURN(1);
} while ((tbl= tbl_it++));
temp_fields.append(fields_for_table[cnt]);
/* Make an unique key over the first field to avoid duplicated updates */
bzero((char*) &group, sizeof(group));
group.direction= ORDER::ORDER_ASC;
group.item= (Item**) temp_fields.head_ref();
tmp_param->quick_group= 1;
tmp_param->field_count= temp_fields.elements;
tmp_param->func_count= temp_fields.elements - 1;
calc_group_buffer(tmp_param, &group);
/* small table, ignore @@big_tables */
my_bool save_big_tables= thd->variables.big_tables;
thd->variables.big_tables= FALSE;
tmp_tables[cnt]=create_tmp_table(thd, tmp_param, temp_fields,
(ORDER*) &group, 0, 0,
TMP_TABLE_ALL_COLUMNS, HA_POS_ERROR, &empty_clex_str);
thd->variables.big_tables= save_big_tables;
if (!tmp_tables[cnt])
DBUG_RETURN(1);
tmp_tables[cnt]->file->extra(HA_EXTRA_WRITE_CACHE);
}
join->tmp_table_keep_current_rowid= TRUE;
DBUG_RETURN(0);
}
static TABLE *item_rowid_table(Item *item)
{
if (item->type() != Item::FUNC_ITEM)
return NULL;
Item_func *func= (Item_func *)item;
if (func->functype() != Item_func::TEMPTABLE_ROWID)
return NULL;
Item_temptable_rowid *itr= (Item_temptable_rowid *)func;
return itr->table;
}
/*
multi_update stores a rowid and new field values for every updated row in a
temporary table (one temporary table per updated table). These rowids are
obtained via Item_temptable_rowid's by calling handler::position(). But if
the join is resolved via a temp table, rowids cannot be obtained from
handler::position() in the multi_update::send_data(). So, they're stored in
the join's temp table (JOIN::add_fields_for_current_rowid()) and here we
replace Item_temptable_rowid's (that would've done handler::position()) with
Item_field's (that will simply take the corresponding field value from the
temp table).
*/
int multi_update::prepare2(JOIN *join)
{
if (!join->need_tmp || !join->tmp_table_keep_current_rowid)
return 0;
// there cannot be many tmp tables in multi-update
JOIN_TAB *tmptab= join->join_tab + join->exec_join_tab_cnt();
for (Item **it= tmptab->tmp_table_param->items_to_copy; *it ; it++)
{
TABLE *tbl= item_rowid_table(*it);
if (!tbl)
continue;
for (uint i= 0; i < table_count; i++)
{
for (Item **it2= tmp_table_param[i].items_to_copy; *it2; it2++)
{
if (item_rowid_table(*it2) != tbl)
continue;
Item_field *fld= new (thd->mem_root)
Item_field(thd, (*it)->get_tmp_table_field());
if (!fld)
return 1;
fld->result_field= (*it2)->get_tmp_table_field();
*it2= fld;
}
}
}
return 0;
}
multi_update::~multi_update()
{
TABLE_LIST *table;
for (table= update_tables ; table; table= table->next_local)
{
table->table->no_keyread= 0;
if (ignore)
table->table->file->extra(HA_EXTRA_NO_IGNORE_DUP_KEY);
}
if (tmp_tables)
{
for (uint cnt = 0; cnt < table_count; cnt++)
{
if (tmp_tables[cnt])
{
free_tmp_table(thd, tmp_tables[cnt]);
tmp_table_param[cnt].cleanup();
}
}
}
if (copy_field)
delete [] copy_field;
thd->count_cuted_fields= CHECK_FIELD_IGNORE; // Restore this setting
DBUG_ASSERT(trans_safe || !updated ||
thd->transaction->all.modified_non_trans_table);
}
int multi_update::send_data(List<Item> &not_used_values)
{
TABLE_LIST *cur_table;
DBUG_ENTER("multi_update::send_data");
for (cur_table= update_tables; cur_table; cur_table= cur_table->next_local)
{
int error= 0;
TABLE *table= cur_table->table;
uint offset= cur_table->shared;
/*
Check if we are using outer join and we didn't find the row
or if we have already updated this row in the previous call to this
function.
The same row may be presented here several times in a join of type
UPDATE t1 FROM t1,t2 SET t1.a=t2.a
In this case we will do the update for the first found row combination.
The join algorithm guarantees that we will not find the a row in
t1 several times.
*/
if (table->status & (STATUS_NULL_ROW | STATUS_UPDATED))
continue;
if (table == table_to_update)
{
/*
We can use compare_record() to optimize away updates if
the table handler is returning all columns OR if
if all updated columns are read
*/
bool can_compare_record;
can_compare_record= records_are_comparable(table);
table->status|= STATUS_UPDATED;
store_record(table,record[1]);
if (fill_record_n_invoke_before_triggers(thd, table,
*fields_for_table[offset],
*values_for_table[offset], 0,
TRG_EVENT_UPDATE))
DBUG_RETURN(1);
/*
Reset the table->auto_increment_field_not_null as it is valid for
only one row.
*/
table->auto_increment_field_not_null= FALSE;
found++;
if (!can_compare_record || compare_record(table))
{
if ((error= cur_table->view_check_option(thd, ignore)) !=
VIEW_CHECK_OK)
{
found--;
if (error == VIEW_CHECK_SKIP)
continue;
else if (unlikely(error == VIEW_CHECK_ERROR))
DBUG_RETURN(1);
}
if (unlikely(!updated++))
{
/*
Inform the main table that we are going to update the table even
while we may be scanning it. This will flush the read cache
if it's used.
*/
main_table->file->extra(HA_EXTRA_PREPARE_FOR_UPDATE);
}
if (unlikely((error=table->file->ha_update_row(table->record[1],
table->record[0]))) &&
error != HA_ERR_RECORD_IS_THE_SAME)
{
updated--;
if (!ignore ||
table->file->is_fatal_error(error, HA_CHECK_ALL))
goto error;
}
else
{
if (unlikely(error == HA_ERR_RECORD_IS_THE_SAME))
{
error= 0;
updated--;
}
else if (has_vers_fields && table->versioned(VERS_TRX_ID))
{
updated_sys_ver++;
}
/* non-transactional or transactional table got modified */
/* either multi_update class' flag is raised in its branch */
if (table->file->has_transactions_and_rollback())
transactional_tables= TRUE;
else
{
trans_safe= FALSE;
thd->transaction->stmt.modified_non_trans_table= TRUE;
}
}
}
if (has_vers_fields && table->versioned(VERS_TIMESTAMP))
{
store_record(table, record[2]);
if (unlikely(error= vers_insert_history_row(table)))
{
restore_record(table, record[2]);
goto error;
}
restore_record(table, record[2]);
updated_sys_ver++;
}
if (table->triggers &&
unlikely(table->triggers->process_triggers(thd, TRG_EVENT_UPDATE,
TRG_ACTION_AFTER, TRUE)))
DBUG_RETURN(1);
}
else
{
TABLE *tmp_table= tmp_tables[offset];
if (copy_funcs(tmp_table_param[offset].items_to_copy, thd))
DBUG_RETURN(1);
/* rowid field is NULL if join tmp table has null row from outer join */
if (tmp_table->field[0]->is_null())
continue;
/* Store regular updated fields in the row. */
DBUG_ASSERT(1 + unupdated_check_opt_tables.elements ==
tmp_table_param[offset].func_count);
fill_record(thd, tmp_table,
tmp_table->field + 1 + unupdated_check_opt_tables.elements,
*values_for_table[offset], true, false, false);
/* Write row, ignoring duplicated updates to a row */
error= tmp_table->file->ha_write_tmp_row(tmp_table->record[0]);
found++;
if (unlikely(error))
{
found--;
if (error != HA_ERR_FOUND_DUPP_KEY &&
error != HA_ERR_FOUND_DUPP_UNIQUE)
{
if (create_internal_tmp_table_from_heap(thd, tmp_table,
tmp_table_param[offset].start_recinfo,
&tmp_table_param[offset].recinfo,
error, 1, NULL))
{
do_update= 0;
DBUG_RETURN(1); // Not a table_is_full error
}
found++;
}
}
}
continue;
error:
DBUG_ASSERT(error > 0);
/*
If (ignore && error == is ignorable) we don't have to
do anything; otherwise...
*/
myf flags= 0;
if (table->file->is_fatal_error(error, HA_CHECK_ALL))
flags|= ME_FATAL; /* Other handler errors are fatal */
prepare_record_for_error_message(error, table);
table->file->print_error(error,MYF(flags));
DBUG_RETURN(1);
} // for (cur_table)
DBUG_RETURN(0);
}
void multi_update::abort_result_set()
{
/* the error was handled or nothing deleted and no side effects return */
if (unlikely(error_handled ||
(!thd->transaction->stmt.modified_non_trans_table && !updated)))
return;
/* Something already updated so we have to invalidate cache */
if (updated)
query_cache_invalidate3(thd, update_tables, 1);
/*
If all tables that has been updated are trans safe then just do rollback.
If not attempt to do remaining updates.
*/
if (! trans_safe)
{
DBUG_ASSERT(thd->transaction->stmt.modified_non_trans_table);
if (do_update && table_count > 1)
{
/* Add warning here */
(void) do_updates();
}
}
if (thd->transaction->stmt.modified_non_trans_table)
{
/*
The query has to binlog because there's a modified non-transactional table
either from the query's list or via a stored routine: bug#13270,23333
*/
if (WSREP_EMULATE_BINLOG(thd) || mysql_bin_log.is_open())
{
/*
THD::killed status might not have been set ON at time of an error
got caught and if happens later the killed error is written
into repl event.
*/
int errcode= query_error_code(thd, thd->killed == NOT_KILLED);
/* the error of binary logging is ignored */
(void)thd->binlog_query(THD::ROW_QUERY_TYPE,
thd->query(), thd->query_length(),
transactional_tables, FALSE, FALSE, errcode);
}
thd->transaction->all.modified_non_trans_table= TRUE;
}
thd->transaction->all.m_unsafe_rollback_flags|=
(thd->transaction->stmt.m_unsafe_rollback_flags & THD_TRANS::DID_WAIT);
DBUG_ASSERT(trans_safe || !updated || thd->transaction->stmt.modified_non_trans_table);
}
int multi_update::do_updates()
{
TABLE_LIST *cur_table;
int local_error= 0;
ha_rows org_updated;
TABLE *table, *tmp_table, *err_table;
List_iterator_fast<TABLE> check_opt_it(unupdated_check_opt_tables);
DBUG_ENTER("multi_update::do_updates");
do_update= 0; // Don't retry this function
if (!found)
DBUG_RETURN(0);
/*
Update read_set to include all fields that virtual columns may depend on.
Usually they're already in the read_set, but if the previous access
method was keyread, only the virtual column itself will be in read_set,
not its dependencies
*/
while(TABLE *tbl= check_opt_it++)
if (Field **vf= tbl->vfield)
for (; *vf; vf++)
if (bitmap_is_set(tbl->read_set, (*vf)->field_index))
(*vf)->vcol_info->expr->walk(&Item::register_field_in_read_map, 1, 0);
for (cur_table= update_tables; cur_table; cur_table= cur_table->next_local)
{
bool can_compare_record;
uint offset= cur_table->shared;
table = cur_table->table;
if (table == table_to_update)
continue; // Already updated
org_updated= updated;
tmp_table= tmp_tables[cur_table->shared];
tmp_table->file->extra(HA_EXTRA_CACHE); // Change to read cache
if (unlikely((local_error= table->file->ha_rnd_init(0))))
{
err_table= table;
goto err;
}
table->file->extra(HA_EXTRA_NO_CACHE);
/*
We have to clear the base record, if we have virtual indexed
blob fields, as some storage engines will access the blob fields
to calculate the keys to see if they have changed. Without
clearing the blob pointers will contain random values which can
cause a crash.
This is a workaround for engines that access columns not present in
either read or write set.
*/
if (table->vfield)
empty_record(table);
has_vers_fields= table->vers_check_update(*fields);
check_opt_it.rewind();
while(TABLE *tbl= check_opt_it++)
{
if (unlikely((local_error= tbl->file->ha_rnd_init(0))))
{
err_table= tbl;
goto err;
}
tbl->file->extra(HA_EXTRA_CACHE);
}
/*
Setup copy functions to copy fields from temporary table
*/
List_iterator_fast<Item> field_it(*fields_for_table[offset]);
Field **field;
Copy_field *copy_field_ptr= copy_field, *copy_field_end;
/* Skip row pointers */
field= tmp_table->field + 1 + unupdated_check_opt_tables.elements;
for ( ; *field ; field++)
{
Item_field *item= (Item_field* ) field_it++;
(copy_field_ptr++)->set(item->field, *field, 0);
}
copy_field_end=copy_field_ptr;
if (unlikely((local_error= tmp_table->file->ha_rnd_init(1))))
{
err_table= tmp_table;
goto err;
}
can_compare_record= records_are_comparable(table);
for (;;)
{
if (thd->killed && trans_safe)
{
thd->fatal_error();
goto err2;
}
if (unlikely((local_error=
tmp_table->file->ha_rnd_next(tmp_table->record[0]))))
{
if (local_error == HA_ERR_END_OF_FILE)
break;
err_table= tmp_table;
goto err;
}
/* call rnd_pos() using rowids from temporary table */
check_opt_it.rewind();
TABLE *tbl= table;
uint field_num= 0;
do
{
DBUG_ASSERT(!tmp_table->field[field_num]->is_null());
String rowid;
tmp_table->field[field_num]->val_str(&rowid);
if (unlikely((local_error= tbl->file->ha_rnd_pos(tbl->record[0],
(uchar*)rowid.ptr()))))
{
err_table= tbl;
goto err;
}
field_num++;
} while ((tbl= check_opt_it++));
if (table->vfield &&
unlikely(table->update_virtual_fields(table->file,
VCOL_UPDATE_INDEXED_FOR_UPDATE)))
goto err2;
table->status|= STATUS_UPDATED;
store_record(table,record[1]);
/* Copy data from temporary table to current table */
for (copy_field_ptr=copy_field;
copy_field_ptr != copy_field_end;
copy_field_ptr++)
{
(*copy_field_ptr->do_copy)(copy_field_ptr);
copy_field_ptr->to_field->set_has_explicit_value();
}
table->evaluate_update_default_function();
if (table->vfield &&
table->update_virtual_fields(table->file, VCOL_UPDATE_FOR_WRITE))
goto err2;
if (table->triggers &&
table->triggers->process_triggers(thd, TRG_EVENT_UPDATE,
TRG_ACTION_BEFORE, TRUE))
goto err2;
if (!can_compare_record || compare_record(table))
{
int error;
if ((error= cur_table->view_check_option(thd, ignore)) !=
VIEW_CHECK_OK)
{
if (error == VIEW_CHECK_SKIP)
continue;
else if (unlikely(error == VIEW_CHECK_ERROR))
{
thd->fatal_error();
goto err2;
}
}
if (has_vers_fields && table->versioned())
table->vers_update_fields();
if (unlikely((local_error=
table->file->ha_update_row(table->record[1],
table->record[0]))) &&
local_error != HA_ERR_RECORD_IS_THE_SAME)
{
if (!ignore ||
table->file->is_fatal_error(local_error, HA_CHECK_ALL))
{
err_table= table;
goto err;
}
}
if (local_error != HA_ERR_RECORD_IS_THE_SAME)
{
updated++;
if (has_vers_fields && table->versioned())
{
if (table->versioned(VERS_TIMESTAMP))
{
store_record(table, record[2]);
if ((local_error= vers_insert_history_row(table)))
{
restore_record(table, record[2]);
err_table = table;
goto err;
}
restore_record(table, record[2]);
}
updated_sys_ver++;
}
}
else
local_error= 0;
}
if (table->triggers &&
unlikely(table->triggers->process_triggers(thd, TRG_EVENT_UPDATE,
TRG_ACTION_AFTER, TRUE)))
goto err2;
}
if (updated != org_updated)
{
if (table->file->has_transactions_and_rollback())
transactional_tables= TRUE;
else
{
trans_safe= FALSE; // Can't do safe rollback
thd->transaction->stmt.modified_non_trans_table= TRUE;
}
}
(void) table->file->ha_rnd_end();
(void) tmp_table->file->ha_rnd_end();
check_opt_it.rewind();
while (TABLE *tbl= check_opt_it++)
tbl->file->ha_rnd_end();
}
DBUG_RETURN(0);
err:
{
prepare_record_for_error_message(local_error, err_table);
err_table->file->print_error(local_error,MYF(ME_FATAL));
}
err2:
if (table->file->inited)
(void) table->file->ha_rnd_end();
if (tmp_table->file->inited)
(void) tmp_table->file->ha_rnd_end();
check_opt_it.rewind();
while (TABLE *tbl= check_opt_it++)
{
if (tbl->file->inited)
(void) tbl->file->ha_rnd_end();
}
if (updated != org_updated)
{
if (table->file->has_transactions_and_rollback())
transactional_tables= TRUE;
else
{
trans_safe= FALSE;
thd->transaction->stmt.modified_non_trans_table= TRUE;
}
}
DBUG_RETURN(1);
}
/* out: 1 if error, 0 if success */
bool multi_update::send_eof()
{
char buff[STRING_BUFFER_USUAL_SIZE];
ulonglong id;
killed_state killed_status= NOT_KILLED;
DBUG_ENTER("multi_update::send_eof");
THD_STAGE_INFO(thd, stage_updating_reference_tables);
/*
Does updates for the last n - 1 tables, returns 0 if ok;
error takes into account killed status gained in do_updates()
*/
int local_error= thd->is_error();
if (likely(!local_error))
local_error = (table_count) ? do_updates() : 0;
/*
if local_error is not set ON until after do_updates() then
later carried out killing should not affect binlogging.
*/
killed_status= (local_error == 0) ? NOT_KILLED : thd->killed;
THD_STAGE_INFO(thd, stage_end);
/* We must invalidate the query cache before binlog writing and
ha_autocommit_... */
if (updated)
{
query_cache_invalidate3(thd, update_tables, 1);
}
/*
Write the SQL statement to the binlog if we updated
rows and we succeeded or if we updated some non
transactional tables.
The query has to binlog because there's a modified non-transactional table
either from the query's list or via a stored routine: bug#13270,23333
*/
if (thd->transaction->stmt.modified_non_trans_table)
thd->transaction->all.modified_non_trans_table= TRUE;
thd->transaction->all.m_unsafe_rollback_flags|=
(thd->transaction->stmt.m_unsafe_rollback_flags & THD_TRANS::DID_WAIT);
if (likely(local_error == 0 ||
thd->transaction->stmt.modified_non_trans_table))
{
if (WSREP_EMULATE_BINLOG(thd) || mysql_bin_log.is_open())
{
int errcode= 0;
if (likely(local_error == 0))
thd->clear_error();
else
errcode= query_error_code(thd, killed_status == NOT_KILLED);
bool force_stmt= false;
for (TABLE *table= all_tables->table; table; table= table->next)
{
if (table->versioned(VERS_TRX_ID))
{
force_stmt= true;
break;
}
}
enum_binlog_format save_binlog_format;
save_binlog_format= thd->get_current_stmt_binlog_format();
if (force_stmt)
thd->set_current_stmt_binlog_format_stmt();
if (thd->binlog_query(THD::ROW_QUERY_TYPE, thd->query(),
thd->query_length(), transactional_tables, FALSE,
FALSE, errcode) > 0)
local_error= 1; // Rollback update
thd->set_current_stmt_binlog_format(save_binlog_format);
}
}
DBUG_ASSERT(trans_safe || !updated ||
thd->transaction->stmt.modified_non_trans_table);
if (unlikely(local_error))
{
error_handled= TRUE; // to force early leave from ::abort_result_set()
if (thd->killed == NOT_KILLED && !thd->get_stmt_da()->is_set())
{
/*
No error message was sent and query was not killed (in which case
mysql_execute_command() will send the error mesage).
*/
my_message(ER_UNKNOWN_ERROR, "An error occurred in multi-table update",
MYF(0));
}
DBUG_RETURN(TRUE);
}
if (!thd->lex->analyze_stmt)
{
id= thd->arg_of_last_insert_id_function ?
thd->first_successful_insert_id_in_prev_stmt : 0;
my_snprintf(buff, sizeof(buff), ER_THD(thd, ER_UPDATE_INFO),
(ulong) found, (ulong) updated, (ulong) thd->cuted_fields);
::my_ok(thd, (thd->client_capabilities & CLIENT_FOUND_ROWS) ? found : updated,
id, buff);
}
DBUG_RETURN(FALSE);
}
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