Classes for query execution. More...

#include <sys/types.h>
#include <string>
#include <vector>
#include "my_alloc.h"
#include "my_inttypes.h"
#include "my_table_map.h"
#include "sql/sql_lex.h"
#include "sql/sql_opt_exec_shared.h"
#include "sql/table.h"
#include "sql/temp_table_param.h"

Classes
struct	SJ_TMP_TABLE_TAB

class	SJ_TMP_TABLE

class	Semijoin_mat_exec
	Executor structure for the materialized semi-join info, which contains. More...

class	QEP_TAB

struct	PendingCondition

struct	PendingInvalidator
	Cache invalidator iterators we need to apply, but cannot yet due to outer joins. More...

Enumerations
enum	Copy_func_type : int { CFT_ALL , CFT_WF_FRAMING , CFT_WF_NON_FRAMING , CFT_WF_NEEDS_PARTITION_CARDINALITY , CFT_WF_USES_ONLY_ONE_ROW , CFT_HAS_NO_WF , CFT_HAS_WF , CFT_WF , CFT_FIELDS }

enum	CallingContext { TOP_LEVEL , DIRECTLY_UNDER_SEMIJOIN , DIRECTLY_UNDER_OUTER_JOIN , DIRECTLY_UNDER_WEEDOUT }

Functions
void	setup_tmptable_write_func (QEP_TAB tab, Opt_trace_object trace)
	Setup write_func of QEP_tmp_table object. More...

bool	copy_fields (Temp_table_param param, const THD thd, bool reverse_copy=false)
	Make a copy of all simple SELECT'ed fields. More...

bool	copy_funcs (Temp_table_param , const THD thd, Copy_func_type type=CFT_ALL)
	Copy result of functions to record in tmp_table. More...

bool	construct_lookup (THD thd, TABLE table, Index_lookup *ref)
	Copy the lookup key into the table ref's key buffer. More...

int	report_handler_error (TABLE *table, int error)
	Help function when we get some an error from the table handler. More...

int	join_read_const_table (JOIN_TAB tab, POSITION pos)
	Reads content of constant table. More...

int	do_sj_dups_weedout (THD thd, SJ_TMP_TABLE sjtbl)
	SemiJoinDuplicateElimination: Weed out duplicate row combinations. More...

int	update_item_cache_if_changed (List< Cached_item > &list)

bool	change_to_use_tmp_fields (mem_root_deque< Item * > fields, THD thd, Ref_item_array ref_item_array, mem_root_deque< Item * > *res_fields, size_t added_non_hidden_fields, bool windowing=false)
	Change all funcs and sum_funcs to fields in tmp table, and create new list of all items. More...

bool	change_to_use_tmp_fields_except_sums (mem_root_deque< Item * > fields, THD thd, Query_block select, Ref_item_array ref_item_array, mem_root_deque< Item > *res_fields, size_t added_non_hidden_fields)
	Change all sum_func refs to fields to point at fields in tmp table. More...

bool	prepare_sum_aggregators (Item_sum **func_ptr, bool need_distinct)

bool	setup_sum_funcs (THD thd, Item_sum *func_ptr)
	Call `setup()` for all sum functions. More...

bool	make_group_fields (JOIN main_join, JOIN curr_join)
	allocate group fields or take prepared (cached). More...

bool	check_unique_fields (TABLE *table)
	Check whether a row is already present in the tmp table. More...

ulonglong	calc_row_hash (TABLE *table)
	Generate hash for unique_constraint for all visible fields of a table. More...

ulonglong	calc_field_hash (const Field field, ulonglong hash)
	Generate hash for a field. More...

int	read_const (TABLE table, Index_lookup ref)

bool	table_rec_cmp (TABLE *table)
	Compare GROUP BY in from tmp table's record[0] and record[1]. More...

bool	set_record_buffer (TABLE *table, double expected_rows_to_fetch)
	Allocate a data buffer that the storage engine can use for fetching batches of records. More...

void	init_tmptable_sum_functions (Item_sum **func_ptr)

void	update_tmptable_sum_func (Item_sum *func_ptr, TABLE tmp_table)
	Update record 0 in tmp_table from record 1. More...

bool	has_rollup_result (Item *item)
	Checks if an item has a ROLLUP NULL which needs to be written to temp table. More...

bool	is_rollup_group_wrapper (const Item *item)

Item *	unwrap_rollup_group (Item *item)

Item *	CreateConjunction (List< Item > *items)
	Create an AND conjunction of all given items. More...

unique_ptr_destroy_only< RowIterator >	PossiblyAttachFilterIterator (unique_ptr_destroy_only< RowIterator > iterator, const std::vector< Item * > &conditions, THD *thd)

void	SplitConditions (Item condition, QEP_TAB current_table, std::vector< Item * > predicates_below_join, std::vector< PendingCondition > predicates_above_join, std::vector< PendingCondition > *join_conditions, plan_idx semi_join_table_idx, qep_tab_map left_tables)

AccessPath *	MoveCompositeIteratorsFromTablePath (THD thd, AccessPath path, const Query_block &query_block)
	For a MATERIALIZE access path, move any non-basic iterators (e.g. More...

AccessPath *	GetAccessPathForDerivedTable (THD thd, Table_ref table_ref, TABLE table, bool rematerialize, Mem_root_array< const AccessPath > invalidators, bool need_rowid, AccessPath table_path)

void	ConvertItemsToCopy (const mem_root_deque< Item * > &items, Field *fields, Temp_table_param param)
	For historical reasons, derived table materialization and temporary table materialization didn't specify the fields to materialize in the same way. More...

std::string	RefToString (const Index_lookup &ref, const KEY &key, bool include_nulls)

bool	MaterializeIsDoingDeduplication (TABLE *table)
	(end of group Query_Executor) More...

bool	ExtractConditions (Item condition, Mem_root_array< Item > *condition_parts)
	Split AND conditions into their constituent parts, recursively. More...

AccessPath *	create_table_access_path (THD thd, TABLE table, AccessPath range_scan, Table_ref table_ref, POSITION *position, bool count_examined_rows)
	create_table_access_path is used to scan by using a number of different methods. More...

unique_ptr_destroy_only< RowIterator >	init_table_iterator (THD thd, TABLE table, AccessPath range_scan, Table_ref table_ref, POSITION *position, bool ignore_not_found_rows, bool count_examined_rows)
	Creates an iterator for the given table, then calls Init() on the resulting iterator. More...

unique_ptr_destroy_only< RowIterator >	init_table_iterator (THD thd, TABLE table, bool ignore_not_found_rows, bool count_examined_rows)
	A short form for when there's no range scan, recursive CTEs or cost information; just a unique_result or a simple table scan. More...

AccessPath *	ConnectJoins (plan_idx upper_first_idx, plan_idx first_idx, plan_idx last_idx, QEP_TAB qep_tabs, THD thd, CallingContext calling_context, std::vector< PendingCondition > pending_conditions, std::vector< PendingInvalidator > pending_invalidators, std::vector< PendingCondition > pending_join_conditions, qep_tab_map unhandled_duplicates, table_map *conditions_depend_on_outer_tables)

Detailed Description

Classes for query execution.

Enumeration Type Documentation

◆ CallingContext

enum CallingContext

Enumerator
TOP_LEVEL
DIRECTLY_UNDER_SEMIJOIN
DIRECTLY_UNDER_OUTER_JOIN
DIRECTLY_UNDER_WEEDOUT

◆ Copy_func_type

enum Copy_func_type : int

Enumerator
CFT_ALL	In non-windowing step, copies functions.
CFT_WF_FRAMING	In windowing step, copies framing window function, including all grouping aggregates, e.g. SUM, AVG and FIRST_VALUE, LAST_VALUE.
CFT_WF_NON_FRAMING	In windowing step, copies non framing window function, e.g. ROW_NUMBER, RANK, DENSE_RANK, except those that are two_pass cf. copy_two_pass_window_functions which are treated separately.
CFT_WF_NEEDS_PARTITION_CARDINALITY	In windowing step, copies window functions that need frame cardinality, that is we need to read all rows of a partition before we can compute the wf's value for the the first row in the partition.
CFT_WF_USES_ONLY_ONE_ROW	In windowing step, copies framing window functions that read only one row per frame.
CFT_HAS_NO_WF	In first windowing step, copies non-window functions which do not rely on window functions, i.e. those that have Item::has_wf() == false.
CFT_HAS_WF	In final windowing step, copies all non-wf functions. Must be called after all wfs have been evaluated, as non-wf functions may reference wf, e.g. 1+RANK.
CFT_WF	Copies all window functions.
CFT_FIELDS	Copies Item_field only (typically because other functions might depend on those fields).

Function Documentation

◆ ConnectJoins()

AccessPath * ConnectJoins	(	plan_idx	upper_first_idx,
		plan_idx	first_idx,
		plan_idx	last_idx,
		QEP_TAB *	qep_tabs,
		THD *	thd,
		CallingContext	calling_context,
		std::vector< PendingCondition > *	pending_conditions,
		std::vector< PendingInvalidator > *	pending_invalidators,
		std::vector< PendingCondition > *	pending_join_conditions,
		qep_tab_map *	unhandled_duplicates,
		table_map *	conditions_depend_on_outer_tables
	)

◆ create_table_access_path()

AccessPath * create_table_access_path	(	THD *	thd,
		TABLE *	table,
		AccessPath *	range_scan,
		Table_ref *	table_ref,
		POSITION *	position,
		bool	count_examined_rows
	)

create_table_access_path is used to scan by using a number of different methods.

Which method to use is set-up in this call so that you can create an iterator from the returned access path and fetch rows through said iterator afterwards.

Parameters

thd	Thread handle
table	Table the data [originally] comes from
range_scan	AccessPath to scan the table with, or nullptr
table_ref	Position for the table, must be non-nullptr for WITH RECURSIVE
position	Place to get cost information from, or nullptr
count_examined_rows	See AccessPath::count_examined_rows.

◆ init_table_iterator() [1/2]

unique_ptr_destroy_only< RowIterator > init_table_iterator	(	THD *	thd,
		TABLE *	table,
		AccessPath *	range_scan,
		Table_ref *	table_ref,
		POSITION *	position,
		bool	ignore_not_found_rows,
		bool	count_examined_rows
	)

Creates an iterator for the given table, then calls Init() on the resulting iterator.

Unlike create_table_iterator(), this can create iterators for sort buffer results (which are set in the TABLE object during query execution). Returns nullptr on failure.

◆ init_table_iterator() [2/2]

unique_ptr_destroy_only< RowIterator > init_table_iterator	(	THD *	thd,
		TABLE *	table,
		bool	ignore_not_found_rows,
		bool	count_examined_rows
	)

inline

A short form for when there's no range scan, recursive CTEs or cost information; just a unique_result or a simple table scan.

Normally, you should prefer just instantiating an iterator yourself – this is for legacy use only.

◆ MaterializeIsDoingDeduplication()

bool MaterializeIsDoingDeduplication ( TABLE * table )

(end of group Query_Executor)

◆ PossiblyAttachFilterIterator()

unique_ptr_destroy_only< RowIterator > PossiblyAttachFilterIterator	(	unique_ptr_destroy_only< RowIterator >	iterator,
		const std::vector< Item * > &	conditions,
		THD *	thd
	)

◆ SplitConditions()

void SplitConditions	(	Item *	condition,
		QEP_TAB *	current_table,
		std::vector< Item * > *	predicates_below_join,
		std::vector< PendingCondition > *	predicates_above_join,
		std::vector< PendingCondition > *	join_conditions,
		plan_idx	semi_join_table_idx,
		qep_tab_map	left_tables
	)

Classes

Enumerations

Functions