opt_hints.h File Reference

#include <assert.h>
#include <stddef.h>
#include <sys/types.h>
#include "lex_string.h"
#include "m_ctype.h"
#include "m_string.h"
#include "my_compiler.h"
#include "my_inttypes.h"
#include "sql/enum_query_type.h"
#include "sql/mem_root_array.h"
#include "sql/sql_bitmap.h"
#include "sql/sql_show.h"
#include "sql_string.h"

Go to the source code of this file.

Classes
struct	st_opt_hint_info
class	Opt_hints_map
	Opt_hints_map contains information about hint state(specified or not, hint value). More...
class	Opt_hints
	Opt_hints class is used as ancestor for Opt_hints_global, Opt_hints_qb, Opt_hints_table, Opt_hints_key classes. More...
class	Opt_hints_global
	Global level hints. More...
class	Opt_hints_qb
	Query block level hints. More...
class	Compound_key_hint
	Auxiliary class for compound key objects. More...
class	Index_key_hint
	Auxiliary class for JOIN_INDEX, GROUP_INDEX, ORDER_INDEX hints. More...
class	Glob_index_key_hint
	Auxiliary class for INDEX hint. More...
class	Opt_hints_table
	Table level hints. More...
class	Opt_hints_key
	Key level hints. More...
class	Hint_set_var
	Container for set_var object and original variable value. More...
class	Sys_var_hint
	SET_VAR hints. More...

Enumerations
enum	opt_hints_enum {   BKA_HINT_ENUM = 0 , BNL_HINT_ENUM , ICP_HINT_ENUM , MRR_HINT_ENUM ,   NO_RANGE_HINT_ENUM , MAX_EXEC_TIME_HINT_ENUM , QB_NAME_HINT_ENUM , SEMIJOIN_HINT_ENUM ,   SUBQUERY_HINT_ENUM , DERIVED_MERGE_HINT_ENUM , JOIN_PREFIX_HINT_ENUM , JOIN_SUFFIX_HINT_ENUM ,   JOIN_ORDER_HINT_ENUM , JOIN_FIXED_ORDER_HINT_ENUM , INDEX_MERGE_HINT_ENUM , RESOURCE_GROUP_HINT_ENUM ,   SKIP_SCAN_HINT_ENUM , HASH_JOIN_HINT_ENUM , INDEX_HINT_ENUM , JOIN_INDEX_HINT_ENUM ,   GROUP_INDEX_HINT_ENUM , ORDER_INDEX_HINT_ENUM , DERIVED_CONDITION_PUSHDOWN_HINT_ENUM , MAX_HINT_ENUM }
	Hint types, MAX_HINT_ENUM should be always last. More...

Functions
bool	is_compound_hint (opt_hints_enum type_arg)
bool	hint_key_state (const THD *thd, const Table_ref *table, uint keyno, opt_hints_enum type_arg, uint optimizer_switch)
	Returns key hint value if hint is specified, returns optimizer switch value if hint is not specified. More...
bool	hint_table_state (const THD *thd, const Table_ref *table, opt_hints_enum type_arg, uint optimizer_switch)
	Returns table hint value if hint is specified, returns optimizer switch value if hint is not specified. More...
void	append_table_name (const THD *thd, String *str, const LEX_CSTRING *qb_name, const LEX_CSTRING *table_name)
	Append table and query block name. More...
bool	compound_hint_key_enabled (const TABLE *table, uint keyno, opt_hints_enum type_arg)
	Returns true if compound hint state is on with or without specified keys, otherwise returns false. More...
bool	idx_merge_hint_state (THD *thd, const TABLE *table, bool *use_cheapest_index_merge)
	Returns true if index merge hint state is on otherwise returns false. More...
int	cmp_lex_string (const LEX_CSTRING &s, const LEX_CSTRING &t, const CHARSET_INFO *cs)

Enumeration Type Documentation

opt_hints_enum

enum opt_hints_enum

Hint types, MAX_HINT_ENUM should be always last.

This enum should be synchronized with opt_hint_info array(see opt_hints.cc).

Enumerator
BKA_HINT_ENUM
BNL_HINT_ENUM
ICP_HINT_ENUM
MRR_HINT_ENUM
NO_RANGE_HINT_ENUM
MAX_EXEC_TIME_HINT_ENUM
QB_NAME_HINT_ENUM
SEMIJOIN_HINT_ENUM
SUBQUERY_HINT_ENUM
DERIVED_MERGE_HINT_ENUM
JOIN_PREFIX_HINT_ENUM
JOIN_SUFFIX_HINT_ENUM
JOIN_ORDER_HINT_ENUM
JOIN_FIXED_ORDER_HINT_ENUM
INDEX_MERGE_HINT_ENUM
RESOURCE_GROUP_HINT_ENUM
SKIP_SCAN_HINT_ENUM
HASH_JOIN_HINT_ENUM
INDEX_HINT_ENUM
JOIN_INDEX_HINT_ENUM
GROUP_INDEX_HINT_ENUM
ORDER_INDEX_HINT_ENUM
DERIVED_CONDITION_PUSHDOWN_HINT_ENUM
MAX_HINT_ENUM

Function Documentation

append_table_name()

void append_table_name	(	const THD *	thd,
		String *	str,
		const LEX_CSTRING *	qb_name,
		const LEX_CSTRING *	table_name
	)

Append table and query block name.

Parameters

thd	pointer to THD object
str	pointer to String object
qb_name	pointer to query block name, may be null
table_name	pointer to table name

cmp_lex_string()

int cmp_lex_string	(	const LEX_CSTRING &	s,
		const LEX_CSTRING &	t,
		const CHARSET_INFO *	cs
	)

compound_hint_key_enabled()

bool compound_hint_key_enabled	(	const TABLE *	table,
		uint	keyno,
		opt_hints_enum	type_arg
	)

Returns true if compound hint state is on with or without specified keys, otherwise returns false.

If compound hint state is on and hint is specified without indexes, function returns 'true' for any 'keyno' argument. If hint specified with indexes, function returns true only for appropriate 'keyno' index.

Parameters

table	Pointer to TABLE object
keyno	Key number
type_arg	Hint type

Returns

true if compound hint state is on with or without specified keys, otherwise returns false.

hint_key_state()

bool hint_key_state	(	const THD *	thd,
		const Table_ref *	table,
		uint	keyno,
		opt_hints_enum	type_arg,
		uint	optimizer_switch
	)

Returns key hint value if hint is specified, returns optimizer switch value if hint is not specified.

Parameters

thd	Pointer to THD object
table	Pointer to Table_ref object
keyno	Key number
type_arg	Hint type
optimizer_switch	Optimizer switch flag

Returns

key hint value if hint is specified, otherwise optimizer switch value.

hint_table_state()

bool hint_table_state	(	const THD *	thd,
		const Table_ref *	table,
		opt_hints_enum	type_arg,
		uint	optimizer_switch
	)

Returns table hint value if hint is specified, returns optimizer switch value if hint is not specified.

Parameters

thd	Pointer to THD object
table	Pointer to Table_ref object
type_arg	Hint type
optimizer_switch	Optimizer switch flag

Returns

table hint value if hint is specified, otherwise optimizer switch value.

idx_merge_hint_state()

bool idx_merge_hint_state	(	THD *	thd,
		const TABLE *	table,
		bool *	use_cheapest_index_merge
	)

Returns true if index merge hint state is on otherwise returns false.

Parameters

thd	Thread handler
table	Pointer to TABLE object
use_cheapest_index_merge	IN/OUT Returns true if INDEX_MERGE hint is used without any specified key.

Returns

true if index merge hint state is on otherwise returns false.

is_compound_hint()

bool is_compound_hint

(

opt_hints_enum

type_arg

)