mirror of
https://github.com/MariaDB/server.git
synced 2025-01-18 13:02:28 +01:00
74cc73d461
Changes that requires code changes in other code of other storage engines.
(Note that all changes are very straightforward and one should find all issues
by compiling a --debug build and fixing all compiler errors and all
asserts in field.cc while running the test suite),
- New optional handler function introduced: reset()
This is called after every DML statement to make it easy for a handler to
statement specific cleanups.
(The only case it's not called is if force the file to be closed)
- handler::extra(HA_EXTRA_RESET) is removed. Code that was there before
should be moved to handler::reset()
- table->read_set contains a bitmap over all columns that are needed
in the query. read_row() and similar functions only needs to read these
columns
- table->write_set contains a bitmap over all columns that will be updated
in the query. write_row() and update_row() only needs to update these
columns.
The above bitmaps should now be up to date in all context
(including ALTER TABLE, filesort()).
The handler is informed of any changes to the bitmap after
fix_fields() by calling the virtual function
handler::column_bitmaps_signal(). If the handler does caching of
these bitmaps (instead of using table->read_set, table->write_set),
it should redo the caching in this code. as the signal() may be sent
several times, it's probably best to set a variable in the signal
and redo the caching on read_row() / write_row() if the variable was
set.
- Removed the read_set and write_set bitmap objects from the handler class
- Removed all column bit handling functions from the handler class.
(Now one instead uses the normal bitmap functions in my_bitmap.c instead
of handler dedicated bitmap functions)
- field->query_id is removed. One should instead instead check
table->read_set and table->write_set if a field is used in the query.
- handler::extra(HA_EXTRA_RETRIVE_ALL_COLS) and
handler::extra(HA_EXTRA_RETRIEVE_PRIMARY_KEY) are removed. One should now
instead use table->read_set to check for which columns to retrieve.
- If a handler needs to call Field->val() or Field->store() on columns
that are not used in the query, one should install a temporary
all-columns-used map while doing so. For this, we provide the following
functions:
my_bitmap_map *old_map= dbug_tmp_use_all_columns(table, table->read_set);
field->val();
dbug_tmp_restore_column_map(table->read_set, old_map);
and similar for the write map:
my_bitmap_map *old_map= dbug_tmp_use_all_columns(table, table->write_set);
field->val();
dbug_tmp_restore_column_map(table->write_set, old_map);
If this is not done, you will sooner or later hit a DBUG_ASSERT
in the field store() / val() functions.
(For not DBUG binaries, the dbug_tmp_restore_column_map() and
dbug_tmp_restore_column_map() are inline dummy functions and should
be optimized away be the compiler).
- If one needs to temporary set the column map for all binaries (and not
just to avoid the DBUG_ASSERT() in the Field::store() / Field::val()
methods) one should use the functions tmp_use_all_columns() and
tmp_restore_column_map() instead of the above dbug_ variants.
- All 'status' fields in the handler base class (like records,
data_file_length etc) are now stored in a 'stats' struct. This makes
it easier to know what status variables are provided by the base
handler. This requires some trivial variable names in the extra()
function.
- New virtual function handler::records(). This is called to optimize
COUNT(*) if (handler::table_flags() & HA_HAS_RECORDS()) is true.
(stats.records is not supposed to be an exact value. It's only has to
be 'reasonable enough' for the optimizer to be able to choose a good
optimization path).
- Non virtual handler::init() function added for caching of virtual
constants from engine.
- Removed has_transactions() virtual method. Now one should instead return
HA_NO_TRANSACTIONS in table_flags() if the table handler DOES NOT support
transactions.
- The 'xxxx_create_handler()' function now has a MEM_ROOT_root argument
that is to be used with 'new handler_name()' to allocate the handler
in the right area. The xxxx_create_handler() function is also
responsible for any initialization of the object before returning.
For example, one should change:
static handler *myisam_create_handler(TABLE_SHARE *table)
{
return new ha_myisam(table);
}
->
static handler *myisam_create_handler(TABLE_SHARE *table, MEM_ROOT *mem_root)
{
return new (mem_root) ha_myisam(table);
}
- New optional virtual function: use_hidden_primary_key().
This is called in case of an update/delete when
(table_flags() and HA_PRIMARY_KEY_REQUIRED_FOR_DELETE) is defined
but we don't have a primary key. This allows the handler to take precisions
in remembering any hidden primary key to able to update/delete any
found row. The default handler marks all columns to be read.
- handler::table_flags() now returns a ulonglong (to allow for more flags).
- New/changed table_flags()
- HA_HAS_RECORDS Set if ::records() is supported
- HA_NO_TRANSACTIONS Set if engine doesn't support transactions
- HA_PRIMARY_KEY_REQUIRED_FOR_DELETE
Set if we should mark all primary key columns for
read when reading rows as part of a DELETE
statement. If there is no primary key,
all columns are marked for read.
- HA_PARTIAL_COLUMN_READ Set if engine will not read all columns in some
cases (based on table->read_set)
- HA_PRIMARY_KEY_ALLOW_RANDOM_ACCESS
Renamed to HA_PRIMARY_KEY_REQUIRED_FOR_POSITION.
- HA_DUPP_POS Renamed to HA_DUPLICATE_POS
- HA_REQUIRES_KEY_COLUMNS_FOR_DELETE
Set this if we should mark ALL key columns for
read when when reading rows as part of a DELETE
statement. In case of an update we will mark
all keys for read for which key part changed
value.
- HA_STATS_RECORDS_IS_EXACT
Set this if stats.records is exact.
(This saves us some extra records() calls
when optimizing COUNT(*))
- Removed table_flags()
- HA_NOT_EXACT_COUNT Now one should instead use HA_HAS_RECORDS if
handler::records() gives an exact count() and
HA_STATS_RECORDS_IS_EXACT if stats.records is exact.
- HA_READ_RND_SAME Removed (no one supported this one)
- Removed not needed functions ha_retrieve_all_cols() and ha_retrieve_all_pk()
- Renamed handler::dupp_pos to handler::dup_pos
- Removed not used variable handler::sortkey
Upper level handler changes:
- ha_reset() now does some overall checks and calls ::reset()
- ha_table_flags() added. This is a cached version of table_flags(). The
cache is updated on engine creation time and updated on open.
MySQL level changes (not obvious from the above):
- DBUG_ASSERT() added to check that column usage matches what is set
in the column usage bit maps. (This found a LOT of bugs in current
column marking code).
- In 5.1 before, all used columns was marked in read_set and only updated
columns was marked in write_set. Now we only mark columns for which we
need a value in read_set.
- Column bitmaps are created in open_binary_frm() and open_table_from_share().
(Before this was in table.cc)
- handler::table_flags() calls are replaced with handler::ha_table_flags()
- For calling field->val() you must have the corresponding bit set in
table->read_set. For calling field->store() you must have the
corresponding bit set in table->write_set. (There are asserts in
all store()/val() functions to catch wrong usage)
- thd->set_query_id is renamed to thd->mark_used_columns and instead
of setting this to an integer value, this has now the values:
MARK_COLUMNS_NONE, MARK_COLUMNS_READ, MARK_COLUMNS_WRITE
Changed also all variables named 'set_query_id' to mark_used_columns.
- In filesort() we now inform the handler of exactly which columns are needed
doing the sort and choosing the rows.
- The TABLE_SHARE object has a 'all_set' column bitmap one can use
when one needs a column bitmap with all columns set.
(This is used for table->use_all_columns() and other places)
- The TABLE object has 3 column bitmaps:
- def_read_set Default bitmap for columns to be read
- def_write_set Default bitmap for columns to be written
- tmp_set Can be used as a temporary bitmap when needed.
The table object has also two pointer to bitmaps read_set and write_set
that the handler should use to find out which columns are used in which way.
- count() optimization now calls handler::records() instead of using
handler->stats.records (if (table_flags() & HA_HAS_RECORDS) is true).
- Added extra argument to Item::walk() to indicate if we should also
traverse sub queries.
- Added TABLE parameter to cp_buffer_from_ref()
- Don't close tables created with CREATE ... SELECT but keep them in
the table cache. (Faster usage of newly created tables).
New interfaces:
- table->clear_column_bitmaps() to initialize the bitmaps for tables
at start of new statements.
- table->column_bitmaps_set() to set up new column bitmaps and signal
the handler about this.
- table->column_bitmaps_set_no_signal() for some few cases where we need
to setup new column bitmaps but don't signal the handler (as the handler
has already been signaled about these before). Used for the momement
only in opt_range.cc when doing ROR scans.
- table->use_all_columns() to install a bitmap where all columns are marked
as use in the read and the write set.
- table->default_column_bitmaps() to install the normal read and write
column bitmaps, but not signaling the handler about this.
This is mainly used when creating TABLE instances.
- table->mark_columns_needed_for_delete(),
table->mark_columns_needed_for_delete() and
table->mark_columns_needed_for_insert() to allow us to put additional
columns in column usage maps if handler so requires.
(The handler indicates what it neads in handler->table_flags())
- table->prepare_for_position() to allow us to tell handler that it
needs to read primary key parts to be able to store them in
future table->position() calls.
(This replaces the table->file->ha_retrieve_all_pk function)
- table->mark_auto_increment_column() to tell handler are going to update
columns part of any auto_increment key.
- table->mark_columns_used_by_index() to mark all columns that is part of
an index. It will also send extra(HA_EXTRA_KEYREAD) to handler to allow
it to quickly know that it only needs to read colums that are part
of the key. (The handler can also use the column map for detecting this,
but simpler/faster handler can just monitor the extra() call).
- table->mark_columns_used_by_index_no_reset() to in addition to other columns,
also mark all columns that is used by the given key.
- table->restore_column_maps_after_mark_index() to restore to default
column maps after a call to table->mark_columns_used_by_index().
- New item function register_field_in_read_map(), for marking used columns
in table->read_map. Used by filesort() to mark all used columns
- Maintain in TABLE->merge_keys set of all keys that are used in query.
(Simplices some optimization loops)
- Maintain Field->part_of_key_not_clustered which is like Field->part_of_key
but the field in the clustered key is not assumed to be part of all index.
(used in opt_range.cc for faster loops)
- dbug_tmp_use_all_columns(), dbug_tmp_restore_column_map()
tmp_use_all_columns() and tmp_restore_column_map() functions to temporally
mark all columns as usable. The 'dbug_' version is primarily intended
inside a handler when it wants to just call Field:store() & Field::val()
functions, but don't need the column maps set for any other usage.
(ie:: bitmap_is_set() is never called)
- We can't use compare_records() to skip updates for handlers that returns
a partial column set and the read_set doesn't cover all columns in the
write set. The reason for this is that if we have a column marked only for
write we can't in the MySQL level know if the value changed or not.
The reason this worked before was that MySQL marked all to be written
columns as also to be read. The new 'optimal' bitmaps exposed this 'hidden
bug'.
- open_table_from_share() does not anymore setup temporary MEM_ROOT
object as a thread specific variable for the handler. Instead we
send the to-be-used MEMROOT to get_new_handler().
(Simpler, faster code)
Bugs fixed:
- Column marking was not done correctly in a lot of cases.
(ALTER TABLE, when using triggers, auto_increment fields etc)
(Could potentially result in wrong values inserted in table handlers
relying on that the old column maps or field->set_query_id was correct)
Especially when it comes to triggers, there may be cases where the
old code would cause lost/wrong values for NDB and/or InnoDB tables.
- Split thd->options flag OPTION_STATUS_NO_TRANS_UPDATE to two flags:
OPTION_STATUS_NO_TRANS_UPDATE and OPTION_KEEP_LOG.
This allowed me to remove some wrong warnings about:
"Some non-transactional changed tables couldn't be rolled back"
- Fixed handling of INSERT .. SELECT and CREATE ... SELECT that wrongly reset
(thd->options & OPTION_STATUS_NO_TRANS_UPDATE) which caused us to loose
some warnings about
"Some non-transactional changed tables couldn't be rolled back")
- Fixed use of uninitialized memory in ha_ndbcluster.cc::delete_table()
which could cause delete_table to report random failures.
- Fixed core dumps for some tests when running with --debug
- Added missing FN_LIBCHAR in mysql_rm_tmp_tables()
(This has probably caused us to not properly remove temporary files after
crash)
- slow_logs was not properly initialized, which could maybe cause
extra/lost entries in slow log.
- If we get an duplicate row on insert, change column map to read and
write all columns while retrying the operation. This is required by
the definition of REPLACE and also ensures that fields that are only
part of UPDATE are properly handled. This fixed a bug in NDB and
REPLACE where REPLACE wrongly copied some column values from the replaced
row.
- For table handler that doesn't support NULL in keys, we would give an error
when creating a primary key with NULL fields, even after the fields has been
automaticly converted to NOT NULL.
- Creating a primary key on a SPATIAL key, would fail if field was not
declared as NOT NULL.
Cleanups:
- Removed not used condition argument to setup_tables
- Removed not needed item function reset_query_id_processor().
- Field->add_index is removed. Now this is instead maintained in
(field->flags & FIELD_IN_ADD_INDEX)
- Field->fieldnr is removed (use field->field_index instead)
- New argument to filesort() to indicate that it should return a set of
row pointers (not used columns). This allowed me to remove some references
to sql_command in filesort and should also enable us to return column
results in some cases where we couldn't before.
- Changed column bitmap handling in opt_range.cc to be aligned with TABLE
bitmap, which allowed me to use bitmap functions instead of looping over
all fields to create some needed bitmaps. (Faster and smaller code)
- Broke up found too long lines
- Moved some variable declaration at start of function for better code
readability.
- Removed some not used arguments from functions.
(setup_fields(), mysql_prepare_insert_check_table())
- setup_fields() now takes an enum instead of an int for marking columns
usage.
- For internal temporary tables, use handler::write_row(),
handler::delete_row() and handler::update_row() instead of
handler::ha_xxxx() for faster execution.
- Changed some constants to enum's and define's.
- Using separate column read and write sets allows for easier checking
of timestamp field was set by statement.
- Remove calls to free_io_cache() as this is now done automaticly in ha_reset()
- Don't build table->normalized_path as this is now identical to table->path
(after bar's fixes to convert filenames)
- Fixed some missed DBUG_PRINT(.."%lx") to use "0x%lx" to make it easier to
do comparision with the 'convert-dbug-for-diff' tool.
Things left to do in 5.1:
- We wrongly log failed CREATE TABLE ... SELECT in some cases when using
row based logging (as shown by testcase binlog_row_mix_innodb_myisam.result)
Mats has promised to look into this.
- Test that my fix for CREATE TABLE ... SELECT is indeed correct.
(I added several test cases for this, but in this case it's better that
someone else also tests this throughly).
Lars has promosed to do this.
555 lines
18 KiB
C++
555 lines
18 KiB
C++
/* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult AB
|
|
|
|
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; either version 2 of the License, or
|
|
(at your option) any later version.
|
|
|
|
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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
|
|
|
|
|
|
/* classes to use when handling where clause */
|
|
|
|
#ifdef USE_PRAGMA_INTERFACE
|
|
#pragma interface /* gcc class implementation */
|
|
#endif
|
|
|
|
#include "procedure.h"
|
|
#include <myisam.h>
|
|
|
|
typedef struct keyuse_t {
|
|
TABLE *table;
|
|
Item *val; /* or value if no field */
|
|
table_map used_tables;
|
|
uint key, keypart, optimize;
|
|
key_part_map keypart_map;
|
|
ha_rows ref_table_rows;
|
|
/*
|
|
If true, the comparison this value was created from will not be
|
|
satisfied if val has NULL 'value'.
|
|
*/
|
|
bool null_rejecting;
|
|
} KEYUSE;
|
|
|
|
class store_key;
|
|
|
|
typedef struct st_table_ref
|
|
{
|
|
bool key_err;
|
|
uint key_parts; // num of ...
|
|
uint key_length; // length of key_buff
|
|
int key; // key no
|
|
byte *key_buff; // value to look for with key
|
|
byte *key_buff2; // key_buff+key_length
|
|
store_key **key_copy; //
|
|
Item **items; // val()'s for each keypart
|
|
/*
|
|
(null_rejecting & (1<<i)) means the condition is '=' and no matching
|
|
rows will be produced if items[i] IS NULL (see add_not_null_conds())
|
|
*/
|
|
key_part_map null_rejecting;
|
|
table_map depend_map; // Table depends on these tables.
|
|
/* null byte position in the key_buf. Used for REF_OR_NULL optimization */
|
|
byte *null_ref_key;
|
|
} TABLE_REF;
|
|
|
|
|
|
/*
|
|
CACHE_FIELD and JOIN_CACHE is used on full join to cache records in outer
|
|
table
|
|
*/
|
|
|
|
typedef struct st_cache_field {
|
|
char *str;
|
|
uint length,blob_length;
|
|
Field_blob *blob_field;
|
|
bool strip;
|
|
} CACHE_FIELD;
|
|
|
|
|
|
typedef struct st_join_cache {
|
|
uchar *buff,*pos,*end;
|
|
uint records,record_nr,ptr_record,fields,length,blobs;
|
|
CACHE_FIELD *field,**blob_ptr;
|
|
SQL_SELECT *select;
|
|
} JOIN_CACHE;
|
|
|
|
|
|
/*
|
|
The structs which holds the join connections and join states
|
|
*/
|
|
enum join_type { JT_UNKNOWN,JT_SYSTEM,JT_CONST,JT_EQ_REF,JT_REF,JT_MAYBE_REF,
|
|
JT_ALL, JT_RANGE, JT_NEXT, JT_FT, JT_REF_OR_NULL,
|
|
JT_UNIQUE_SUBQUERY, JT_INDEX_SUBQUERY, JT_INDEX_MERGE};
|
|
|
|
class JOIN;
|
|
|
|
enum enum_nested_loop_state
|
|
{
|
|
NESTED_LOOP_KILLED= -2, NESTED_LOOP_ERROR= -1,
|
|
NESTED_LOOP_OK= 0, NESTED_LOOP_NO_MORE_ROWS= 1,
|
|
NESTED_LOOP_QUERY_LIMIT= 3, NESTED_LOOP_CURSOR_LIMIT= 4
|
|
};
|
|
|
|
typedef enum_nested_loop_state
|
|
(*Next_select_func)(JOIN *, struct st_join_table *, bool);
|
|
typedef int (*Read_record_func)(struct st_join_table *tab);
|
|
Next_select_func setup_end_select_func(JOIN *join);
|
|
|
|
|
|
typedef struct st_join_table {
|
|
st_join_table() {} /* Remove gcc warning */
|
|
TABLE *table;
|
|
KEYUSE *keyuse; /* pointer to first used key */
|
|
SQL_SELECT *select;
|
|
COND *select_cond;
|
|
QUICK_SELECT_I *quick;
|
|
Item **on_expr_ref; /* pointer to the associated on expression */
|
|
COND_EQUAL *cond_equal; /* multiple equalities for the on expression */
|
|
st_join_table *first_inner; /* first inner table for including outerjoin */
|
|
bool found; /* true after all matches or null complement */
|
|
bool not_null_compl;/* true before null complement is added */
|
|
st_join_table *last_inner; /* last table table for embedding outer join */
|
|
st_join_table *first_upper; /* first inner table for embedding outer join */
|
|
st_join_table *first_unmatched; /* used for optimization purposes only */
|
|
const char *info;
|
|
Read_record_func read_first_record;
|
|
Next_select_func next_select;
|
|
READ_RECORD read_record;
|
|
double worst_seeks;
|
|
key_map const_keys; /* Keys with constant part */
|
|
key_map checked_keys; /* Keys checked in find_best */
|
|
key_map needed_reg;
|
|
key_map keys; /* all keys with can be used */
|
|
ha_rows records,found_records,read_time;
|
|
table_map dependent,key_dependent;
|
|
uint use_quick,index;
|
|
uint status; // Save status for cache
|
|
uint used_fields,used_fieldlength,used_blobs;
|
|
enum join_type type;
|
|
bool cached_eq_ref_table,eq_ref_table,not_used_in_distinct;
|
|
bool sorted;
|
|
TABLE_REF ref;
|
|
JOIN_CACHE cache;
|
|
JOIN *join;
|
|
/* Bitmap of nested joins this table is part of */
|
|
nested_join_map embedding_map;
|
|
|
|
void cleanup();
|
|
inline bool is_using_loose_index_scan()
|
|
{
|
|
return (select && select->quick &&
|
|
(select->quick->get_type() ==
|
|
QUICK_SELECT_I::QS_TYPE_GROUP_MIN_MAX));
|
|
}
|
|
} JOIN_TAB;
|
|
|
|
enum_nested_loop_state sub_select_cache(JOIN *join, JOIN_TAB *join_tab, bool
|
|
end_of_records);
|
|
enum_nested_loop_state sub_select(JOIN *join,JOIN_TAB *join_tab, bool
|
|
end_of_records);
|
|
|
|
|
|
typedef struct st_position /* Used in find_best */
|
|
{
|
|
double records_read;
|
|
double read_time;
|
|
JOIN_TAB *table;
|
|
KEYUSE *key;
|
|
} POSITION;
|
|
|
|
typedef struct st_rollup
|
|
{
|
|
enum State { STATE_NONE, STATE_INITED, STATE_READY };
|
|
State state;
|
|
Item_null_result **null_items;
|
|
Item ***ref_pointer_arrays;
|
|
List<Item> *fields;
|
|
} ROLLUP;
|
|
|
|
|
|
class JOIN :public Sql_alloc
|
|
{
|
|
JOIN(const JOIN &rhs); /* not implemented */
|
|
JOIN& operator=(const JOIN &rhs); /* not implemented */
|
|
public:
|
|
JOIN_TAB *join_tab,**best_ref;
|
|
JOIN_TAB **map2table; // mapping between table indexes and JOIN_TABs
|
|
JOIN_TAB *join_tab_save; // saved join_tab for subquery reexecution
|
|
TABLE **table,**all_tables,*sort_by_table;
|
|
uint tables,const_tables;
|
|
uint send_group_parts;
|
|
bool sort_and_group,first_record,full_join,group, no_field_update;
|
|
bool do_send_rows;
|
|
/*
|
|
TRUE when we want to resume nested loop iterations when
|
|
fetching data from a cursor
|
|
*/
|
|
bool resume_nested_loop;
|
|
table_map const_table_map,found_const_table_map,outer_join;
|
|
ha_rows send_records,found_records,examined_rows,row_limit, select_limit;
|
|
/*
|
|
Used to fetch no more than given amount of rows per one
|
|
fetch operation of server side cursor.
|
|
The value is checked in end_send and end_send_group in fashion, similar
|
|
to offset_limit_cnt:
|
|
- fetch_limit= HA_POS_ERROR if there is no cursor.
|
|
- when we open a cursor, we set fetch_limit to 0,
|
|
- on each fetch iteration we add num_rows to fetch to fetch_limit
|
|
*/
|
|
ha_rows fetch_limit;
|
|
POSITION positions[MAX_TABLES+1],best_positions[MAX_TABLES+1];
|
|
|
|
/*
|
|
Bitmap of nested joins embedding the position at the end of the current
|
|
partial join (valid only during join optimizer run).
|
|
*/
|
|
nested_join_map cur_embedding_map;
|
|
|
|
double best_read;
|
|
List<Item> *fields;
|
|
List<Cached_item> group_fields, group_fields_cache;
|
|
TABLE *tmp_table;
|
|
// used to store 2 possible tmp table of SELECT
|
|
TABLE *exec_tmp_table1, *exec_tmp_table2;
|
|
THD *thd;
|
|
Item_sum **sum_funcs, ***sum_funcs_end;
|
|
/* second copy of sumfuncs (for queries with 2 temporary tables */
|
|
Item_sum **sum_funcs2, ***sum_funcs_end2;
|
|
Procedure *procedure;
|
|
Item *having;
|
|
Item *tmp_having; // To store having when processed temporary table
|
|
Item *having_history; // Store having for explain
|
|
ulonglong select_options;
|
|
select_result *result;
|
|
TMP_TABLE_PARAM tmp_table_param;
|
|
MYSQL_LOCK *lock;
|
|
// unit structure (with global parameters) for this select
|
|
SELECT_LEX_UNIT *unit;
|
|
// select that processed
|
|
SELECT_LEX *select_lex;
|
|
|
|
JOIN *tmp_join; // copy of this JOIN to be used with temporary tables
|
|
ROLLUP rollup; // Used with rollup
|
|
|
|
bool select_distinct; // Set if SELECT DISTINCT
|
|
|
|
/*
|
|
simple_xxxxx is set if ORDER/GROUP BY doesn't include any references
|
|
to other tables than the first non-constant table in the JOIN.
|
|
It's also set if ORDER/GROUP BY is empty.
|
|
*/
|
|
bool simple_order, simple_group;
|
|
/*
|
|
Is set only in case if we have a GROUP BY clause
|
|
and no ORDER BY after constant elimination of 'order'.
|
|
*/
|
|
bool no_order;
|
|
/* Is set if we have a GROUP BY and we have ORDER BY on a constant. */
|
|
bool skip_sort_order;
|
|
|
|
bool need_tmp, hidden_group_fields;
|
|
DYNAMIC_ARRAY keyuse;
|
|
Item::cond_result cond_value;
|
|
List<Item> all_fields; // to store all fields that used in query
|
|
//Above list changed to use temporary table
|
|
List<Item> tmp_all_fields1, tmp_all_fields2, tmp_all_fields3;
|
|
//Part, shared with list above, emulate following list
|
|
List<Item> tmp_fields_list1, tmp_fields_list2, tmp_fields_list3;
|
|
List<Item> &fields_list; // hold field list passed to mysql_select
|
|
List<Item> procedure_fields_list;
|
|
int error;
|
|
|
|
ORDER *order, *group_list, *proc_param; //hold parameters of mysql_select
|
|
COND *conds; // ---"---
|
|
Item *conds_history; // store WHERE for explain
|
|
TABLE_LIST *tables_list; //hold 'tables' parameter of mysql_select
|
|
List<TABLE_LIST> *join_list; // list of joined tables in reverse order
|
|
COND_EQUAL *cond_equal;
|
|
SQL_SELECT *select; //created in optimisation phase
|
|
JOIN_TAB *return_tab; //used only for outer joins
|
|
Item **ref_pointer_array; //used pointer reference for this select
|
|
// Copy of above to be used with different lists
|
|
Item **items0, **items1, **items2, **items3, **current_ref_pointer_array;
|
|
uint ref_pointer_array_size; // size of above in bytes
|
|
const char *zero_result_cause; // not 0 if exec must return zero result
|
|
|
|
bool union_part; // this subselect is part of union
|
|
bool optimized; // flag to avoid double optimization in EXPLAIN
|
|
|
|
JOIN(THD *thd_arg, List<Item> &fields_arg, ulonglong select_options_arg,
|
|
select_result *result_arg)
|
|
:fields_list(fields_arg)
|
|
{
|
|
init(thd_arg, fields_arg, select_options_arg, result_arg);
|
|
}
|
|
|
|
void init(THD *thd_arg, List<Item> &fields_arg, ulonglong select_options_arg,
|
|
select_result *result_arg)
|
|
{
|
|
join_tab= join_tab_save= 0;
|
|
table= 0;
|
|
tables= 0;
|
|
const_tables= 0;
|
|
join_list= 0;
|
|
sort_and_group= 0;
|
|
first_record= 0;
|
|
do_send_rows= 1;
|
|
resume_nested_loop= FALSE;
|
|
send_records= 0;
|
|
found_records= 0;
|
|
fetch_limit= HA_POS_ERROR;
|
|
examined_rows= 0;
|
|
exec_tmp_table1= 0;
|
|
exec_tmp_table2= 0;
|
|
thd= thd_arg;
|
|
sum_funcs= sum_funcs2= 0;
|
|
procedure= 0;
|
|
having= tmp_having= having_history= 0;
|
|
select_options= select_options_arg;
|
|
result= result_arg;
|
|
lock= thd_arg->lock;
|
|
select_lex= 0; //for safety
|
|
tmp_join= 0;
|
|
select_distinct= test(select_options & SELECT_DISTINCT);
|
|
no_order= 0;
|
|
simple_order= 0;
|
|
simple_group= 0;
|
|
skip_sort_order= 0;
|
|
need_tmp= 0;
|
|
hidden_group_fields= 0; /*safety*/
|
|
error= 0;
|
|
select= 0;
|
|
return_tab= 0;
|
|
ref_pointer_array= items0= items1= items2= items3= 0;
|
|
ref_pointer_array_size= 0;
|
|
zero_result_cause= 0;
|
|
optimized= 0;
|
|
cond_equal= 0;
|
|
|
|
all_fields= fields_arg;
|
|
fields_list= fields_arg;
|
|
bzero((char*) &keyuse,sizeof(keyuse));
|
|
tmp_table_param.init();
|
|
tmp_table_param.end_write_records= HA_POS_ERROR;
|
|
rollup.state= ROLLUP::STATE_NONE;
|
|
}
|
|
|
|
int prepare(Item ***rref_pointer_array, TABLE_LIST *tables, uint wind_num,
|
|
COND *conds, uint og_num, ORDER *order, ORDER *group,
|
|
Item *having, ORDER *proc_param, SELECT_LEX *select,
|
|
SELECT_LEX_UNIT *unit);
|
|
int optimize();
|
|
int reinit();
|
|
void exec();
|
|
int destroy();
|
|
void restore_tmp();
|
|
bool alloc_func_list();
|
|
bool make_sum_func_list(List<Item> &all_fields, List<Item> &send_fields,
|
|
bool before_group_by, bool recompute= FALSE);
|
|
|
|
inline void set_items_ref_array(Item **ptr)
|
|
{
|
|
memcpy((char*) ref_pointer_array, (char*) ptr, ref_pointer_array_size);
|
|
current_ref_pointer_array= ptr;
|
|
}
|
|
inline void init_items_ref_array()
|
|
{
|
|
items0= ref_pointer_array + all_fields.elements;
|
|
memcpy(items0, ref_pointer_array, ref_pointer_array_size);
|
|
current_ref_pointer_array= items0;
|
|
}
|
|
|
|
bool rollup_init();
|
|
bool rollup_make_fields(List<Item> &all_fields, List<Item> &fields,
|
|
Item_sum ***func);
|
|
int rollup_send_data(uint idx);
|
|
int rollup_write_data(uint idx, TABLE *table);
|
|
bool test_in_subselect(Item **where);
|
|
/*
|
|
Release memory and, if possible, the open tables held by this execution
|
|
plan (and nested plans). It's used to release some tables before
|
|
the end of execution in order to increase concurrency and reduce
|
|
memory consumption.
|
|
*/
|
|
void join_free();
|
|
/* Cleanup this JOIN, possibly for reuse */
|
|
void cleanup(bool full);
|
|
void clear();
|
|
bool save_join_tab();
|
|
bool send_row_on_empty_set()
|
|
{
|
|
return (do_send_rows && tmp_table_param.sum_func_count != 0 &&
|
|
!group_list);
|
|
}
|
|
bool change_result(select_result *result);
|
|
bool is_top_level_join() const
|
|
{
|
|
return (unit == &thd->lex->unit && (unit->fake_select_lex == 0 ||
|
|
select_lex == unit->fake_select_lex));
|
|
}
|
|
};
|
|
|
|
|
|
typedef struct st_select_check {
|
|
uint const_ref,reg_ref;
|
|
} SELECT_CHECK;
|
|
|
|
extern const char *join_type_str[];
|
|
void TEST_join(JOIN *join);
|
|
|
|
/* Extern functions in sql_select.cc */
|
|
bool store_val_in_field(Field *field,Item *val);
|
|
TABLE *create_tmp_table(THD *thd,TMP_TABLE_PARAM *param,List<Item> &fields,
|
|
ORDER *group, bool distinct, bool save_sum_fields,
|
|
ulonglong select_options, ha_rows rows_limit,
|
|
char* alias);
|
|
void free_tmp_table(THD *thd, TABLE *entry);
|
|
void count_field_types(TMP_TABLE_PARAM *param, List<Item> &fields,
|
|
bool reset_with_sum_func);
|
|
bool setup_copy_fields(THD *thd, TMP_TABLE_PARAM *param,
|
|
Item **ref_pointer_array,
|
|
List<Item> &new_list1, List<Item> &new_list2,
|
|
uint elements, List<Item> &fields);
|
|
void copy_fields(TMP_TABLE_PARAM *param);
|
|
void copy_funcs(Item **func_ptr);
|
|
bool create_myisam_from_heap(THD *thd, TABLE *table, TMP_TABLE_PARAM *param,
|
|
int error, bool ignore_last_dupp_error);
|
|
uint find_shortest_key(TABLE *table, const key_map *usable_keys);
|
|
Field* create_tmp_field_from_field(THD *thd, Field* org_field,
|
|
const char *name, TABLE *table,
|
|
Item_field *item, uint convert_blob_length);
|
|
|
|
/* functions from opt_sum.cc */
|
|
bool simple_pred(Item_func *func_item, Item **args, bool *inv_order);
|
|
int opt_sum_query(TABLE_LIST *tables, List<Item> &all_fields,COND *conds);
|
|
|
|
/* from sql_delete.cc, used by opt_range.cc */
|
|
extern "C" int refpos_order_cmp(void* arg, const void *a,const void *b);
|
|
|
|
/* class to copying an field/item to a key struct */
|
|
|
|
class store_key :public Sql_alloc
|
|
{
|
|
protected:
|
|
Field *to_field; // Store data here
|
|
char *null_ptr;
|
|
char err;
|
|
public:
|
|
enum store_key_result { STORE_KEY_OK, STORE_KEY_FATAL, STORE_KEY_CONV };
|
|
store_key(THD *thd, Field *field_arg, char *ptr, char *null, uint length)
|
|
:null_ptr(null),err(0)
|
|
{
|
|
if (field_arg->type() == FIELD_TYPE_BLOB)
|
|
{
|
|
/* Key segments are always packed with a 2 byte length prefix */
|
|
to_field= new Field_varstring(ptr, length, 2, (uchar*) null, 1,
|
|
Field::NONE, field_arg->field_name,
|
|
field_arg->table->s, field_arg->charset());
|
|
to_field->init(field_arg->table);
|
|
}
|
|
else
|
|
to_field=field_arg->new_key_field(thd->mem_root, field_arg->table,
|
|
ptr, (uchar*) null, 1);
|
|
}
|
|
virtual ~store_key() {} /* Not actually needed */
|
|
virtual enum store_key_result copy()=0;
|
|
virtual const char *name() const=0;
|
|
};
|
|
|
|
|
|
class store_key_field: public store_key
|
|
{
|
|
Copy_field copy_field;
|
|
const char *field_name;
|
|
public:
|
|
store_key_field(THD *thd, Field *to_field_arg, char *ptr, char *null_ptr_arg,
|
|
uint length, Field *from_field, const char *name_arg)
|
|
:store_key(thd, to_field_arg,ptr,
|
|
null_ptr_arg ? null_ptr_arg : from_field->maybe_null() ? &err
|
|
: NullS,length), field_name(name_arg)
|
|
{
|
|
if (to_field)
|
|
{
|
|
copy_field.set(to_field,from_field,0);
|
|
}
|
|
}
|
|
enum store_key_result copy()
|
|
{
|
|
TABLE *table= copy_field.to_field->table;
|
|
my_bitmap_map *old_map= dbug_tmp_use_all_columns(table,
|
|
table->write_set);
|
|
copy_field.do_copy(©_field);
|
|
dbug_tmp_restore_column_map(table->write_set, old_map);
|
|
return err != 0 ? STORE_KEY_FATAL : STORE_KEY_OK;
|
|
}
|
|
const char *name() const { return field_name; }
|
|
};
|
|
|
|
|
|
class store_key_item :public store_key
|
|
{
|
|
protected:
|
|
Item *item;
|
|
public:
|
|
store_key_item(THD *thd, Field *to_field_arg, char *ptr, char *null_ptr_arg,
|
|
uint length, Item *item_arg)
|
|
:store_key(thd, to_field_arg,ptr,
|
|
null_ptr_arg ? null_ptr_arg : item_arg->maybe_null ?
|
|
&err : NullS, length), item(item_arg)
|
|
{}
|
|
enum store_key_result copy()
|
|
{
|
|
TABLE *table= to_field->table;
|
|
my_bitmap_map *old_map= dbug_tmp_use_all_columns(table,
|
|
table->write_set);
|
|
int res= item->save_in_field(to_field, 1);
|
|
dbug_tmp_restore_column_map(table->write_set, old_map);
|
|
return (err != 0 || res > 2 ? STORE_KEY_FATAL : (store_key_result) res);
|
|
|
|
}
|
|
const char *name() const { return "func"; }
|
|
};
|
|
|
|
|
|
class store_key_const_item :public store_key_item
|
|
{
|
|
bool inited;
|
|
public:
|
|
store_key_const_item(THD *thd, Field *to_field_arg, char *ptr,
|
|
char *null_ptr_arg, uint length,
|
|
Item *item_arg)
|
|
:store_key_item(thd, to_field_arg,ptr,
|
|
null_ptr_arg ? null_ptr_arg : item_arg->maybe_null ?
|
|
&err : NullS, length, item_arg), inited(0)
|
|
{
|
|
}
|
|
enum store_key_result copy()
|
|
{
|
|
int res;
|
|
if (!inited)
|
|
{
|
|
inited=1;
|
|
if ((res= item->save_in_field(to_field, 1)))
|
|
{
|
|
if (!err)
|
|
err= res;
|
|
}
|
|
}
|
|
return (err > 2 ? STORE_KEY_FATAL : (store_key_result) err);
|
|
}
|
|
const char *name() const { return "const"; }
|
|
};
|
|
|
|
bool cp_buffer_from_ref(THD *thd, TABLE *table, TABLE_REF *ref);
|
|
bool error_if_full_join(JOIN *join);
|
|
int report_error(TABLE *table, int error);
|
|
int safe_index_read(JOIN_TAB *tab);
|
|
COND *remove_eq_conds(THD *thd, COND *cond, Item::cond_result *cond_value);
|