Inheritance diagram for Item_in_optimizer:

Collaboration diagram for Item_in_optimizer:

Public Member Functions
	Item_in_optimizer (Item a, Item_in_subselect b)
bool	fix_fields (THD , Item *)
bool	fix_left (THD thd, Item *ref)
void	fix_after_pullout (st_select_lex parent_select, st_select_lex removed_select)
bool	is_null ()
longlong	val_int ()
void	cleanup ()
const char *	func_name () const
Item_cache **	get_cache ()
void	keep_top_level_cache ()
Item *	transform (Item_transformer transformer, uchar *arg)
Public Member Functions inherited from Item_bool_func
	Item_bool_func (Item *a)
	Item_bool_func (Item a, Item b)
	Item_bool_func (THD thd, Item_bool_func item)
bool	is_bool_func ()
void	fix_length_and_dec ()
uint	decimal_precision () const
virtual bool	created_by_in2exists () const
	Whether this Item was created by the IN->EXISTS subquery transformation.
void	set_created_by_in2exists ()
Public Member Functions inherited from Item_int_func
	Item_int_func (Item *a)
	Item_int_func (Item a, Item b)
	Item_int_func (Item a, Item b, Item *c)
	Item_int_func (List< Item > &list)
	Item_int_func (THD thd, Item_int_func item)
double	val_real ()
String *	val_str (String *str)
bool	get_date (MYSQL_TIME *ltime, uint fuzzydate)
bool	get_time (MYSQL_TIME *ltime)
enum Item_result	result_type () const
Public Member Functions inherited from Item_func
enum Type	type () const
virtual enum Functype	functype () const
	Item_func (Item *a)
	Item_func (Item a, Item b)
	Item_func (Item a, Item b, Item *c)
	Item_func (Item a, Item b, Item c, Item d)
	Item_func (Item a, Item b, Item c, Item d, Item *e)
	Item_func (List< Item > &list)
	Item_func (THD thd, Item_func item)
table_map	used_tables () const
virtual table_map	get_initial_pseudo_tables () const
table_map	not_null_tables () const
void	update_used_tables ()
void	set_used_tables (table_map map)
void	set_not_null_tables (table_map map)
bool	eq (const Item *item, bool binary_cmp) const
virtual optimize_type	select_optimize () const
virtual bool	have_rev_func () const
virtual Item *	key_item () const
virtual bool	const_item () const
Item **	arguments () const
void	set_arguments (List< Item > &list)
uint	argument_count () const
void	remove_arguments ()
void	split_sum_func (THD *thd, Ref_ptr_array ref_pointer_array, List< Item > &fields)
virtual void	print (String *str, enum_query_type query_type)
void	print_op (String *str, enum_query_type query_type)
void	print_args (String *str, uint from, enum_query_type query_type)
virtual void	fix_num_length_and_dec ()
void	count_only_length (Item **item, uint nitems)
void	count_real_length ()
void	count_decimal_length ()
void	count_datetime_length (Item **item, uint nitems)
bool	count_string_result_length (enum_field_types field_type, Item **item, uint nitems)
bool	get_arg0_date (MYSQL_TIME *ltime, uint fuzzy_date)
bool	get_arg0_time (MYSQL_TIME *ltime)
void	signal_divide_by_null ()
Field *	tmp_table_field ()
Field *	tmp_table_field (TABLE *t_arg)
Item *	get_tmp_table_item (THD *thd)
my_decimal *	val_decimal (my_decimal *)
bool	agg_arg_charsets (DTCollation &c, Item **items, uint nitems, uint flags, int item_sep)
bool	agg_arg_charsets_for_string_result (DTCollation &c, Item **items, uint nitems, int item_sep=1)
bool	agg_arg_charsets_for_comparison (DTCollation &c, Item **items, uint nitems, int item_sep=1)
bool	agg_arg_charsets_for_string_result_with_comparison (DTCollation &c, Item **items, uint nitems, int item_sep=1)
bool	walk (Item_processor processor, bool walk_subquery, uchar *arg)
Item *	compile (Item_analyzer analyzer, uchar *arg_p, Item_transformer transformer, uchar arg_t)
void	traverse_cond (Cond_traverser traverser, void *arg, traverse_order order)
double	fix_result (double value)
void	raise_numeric_overflow (const char *type_name)
double	raise_float_overflow ()
longlong	raise_integer_overflow ()
int	raise_decimal_overflow ()
double	check_float_overflow (double value)
longlong	check_integer_overflow (longlong value, bool val_unsigned)
int	check_decimal_overflow (int error)
bool	has_timestamp_args ()
bool	has_date_args ()
bool	has_time_args ()
bool	has_datetime_args ()
virtual bool	check_valid_arguments_processor (uchar *bool_arg)
virtual bool	find_function_processor (uchar *arg)
Public Member Functions inherited from Item_result_field
	Item_result_field (THD thd, Item_result_field item)
Field *	get_tmp_table_field ()
void	set_result_field (Field *field)
bool	is_result_field ()
void	save_in_result_field (bool no_conversions)
Public Member Functions inherited from Item
	Item (THD thd, Item item)
void	rename (char *new_name)
void	init_make_field (Send_field *tmp_field, enum enum_field_types type)
virtual void	make_field (Send_field *field)
virtual Field *	make_string_field (TABLE *table)
void	quick_fix_field ()
type_conversion_status	save_in_field_no_warnings (Field *field, bool no_conversions)
virtual type_conversion_status	save_in_field (Field *field, bool no_conversions)
virtual void	save_org_in_field (Field *field)
virtual type_conversion_status	save_safe_in_field (Field *field)
virtual bool	send (Protocol protocol, String str)
virtual enum Item_result	numeric_context_result_type () const
enum Item_result	temporal_with_date_as_number_result_type () const
virtual Item_result	cast_to_int_type () const
virtual enum_field_types	string_field_type () const
virtual enum_field_types	field_type () const
virtual enum_monotonicity_info	get_monotonicity_info () const
virtual longlong	val_int_endpoint (bool left_endp, bool *incl_endp)
virtual longlong	val_date_temporal ()
virtual longlong	val_time_temporal ()
longlong	val_temporal_by_field_type ()
longlong	val_temporal_with_round (enum_field_types type, uint8 dec)
ulonglong	val_uint ()
virtual String *	val_str_ascii (String *str)
virtual bool	val_bool ()
virtual String *	val_nodeset (String *)
type_conversion_status	save_time_in_field (Field *field)
type_conversion_status	save_date_in_field (Field *field)
type_conversion_status	save_str_value_in_field (Field field, String result)
virtual const char *	full_name () const
virtual double	val_result ()
virtual longlong	val_int_result ()
virtual longlong	val_time_temporal_result ()
virtual longlong	val_date_temporal_result ()
virtual String *	str_result (String *tmp)
virtual my_decimal *	val_decimal_result (my_decimal *val)
virtual bool	val_bool_result ()
virtual bool	is_null_result ()
virtual table_map	resolved_used_tables () const
virtual bool	basic_const_item () const
virtual Item *	clone_item ()
virtual cond_result	eq_cmp_result () const
uint	float_length (uint decimals_par) const
int	decimal_int_part () const
virtual uint	time_precision ()
virtual uint	datetime_precision ()
virtual bool	const_during_execution () const
void	print_item_w_name (String *, enum_query_type query_type)
void	print_for_order (String *str, enum_query_type query_type, bool used_alias)
void	split_sum_func2 (THD thd, Ref_ptr_array ref_pointer_array, List< Item > &fields, Item *ref, bool skip_registered)
virtual bool	get_timeval (struct timeval tm, int warnings)
virtual bool	get_date_result (MYSQL_TIME *ltime, uint fuzzydate)
virtual void	update_null_value ()
virtual void	top_level_item ()
virtual void	no_rows_in_result ()
virtual Item *	copy_or_same (THD *thd)
virtual Item *	copy_andor_structure (THD *thd, bool real_items=false)
virtual Item *	real_item ()
virtual const CHARSET_INFO *	compare_collation ()
virtual const CHARSET_INFO *	charset_for_protocol (void) const
virtual bool	intro_version (uchar *int_arg)
virtual bool	remove_dependence_processor (uchar *arg)
virtual bool	remove_fixed (uchar *arg)
virtual bool	cleanup_processor (uchar *arg)
virtual bool	collect_item_field_processor (uchar *arg)
virtual bool	add_field_to_set_processor (uchar *arg)
virtual bool	remove_column_from_bitmap (uchar *arg)
virtual bool	find_item_in_field_list_processor (uchar *arg)
virtual bool	change_context_processor (uchar *context)
virtual bool	reset_query_id_processor (uchar *query_id_arg)
virtual bool	find_item_processor (uchar *arg)
virtual bool	register_field_in_read_map (uchar *arg)
virtual bool	inform_item_in_cond_of_tab (uchar *join_tab_index)
virtual bool	clean_up_after_removal (uchar *arg)
virtual bool	cache_const_expr_analyzer (uchar **arg)
virtual Item *	cache_const_expr_transformer (uchar *arg)
virtual bool	item_field_by_name_analyzer (uchar **arg)
virtual Item *	item_field_by_name_transformer (uchar *arg)
virtual bool	equality_substitution_analyzer (uchar **arg)
virtual Item *	equality_substitution_transformer (uchar *arg)
virtual bool	check_partition_func_processor (uchar *bool_arg)
virtual bool	subst_argument_checker (uchar **arg)
virtual bool	explain_subquery_checker (uchar **arg)
virtual Item *	explain_subquery_propagator (uchar *arg)
virtual Item *	equal_fields_propagator (uchar *arg)
virtual bool	set_no_const_sub (uchar *arg)
virtual Item *	replace_equal_field (uchar *arg)
virtual Item *	this_item ()
virtual const Item *	this_item () const
virtual Item **	this_item_addr (THD thd, Item *addr_arg)
virtual uint	cols ()
virtual Item *	element_index (uint i)
virtual Item **	addr (uint i)
virtual bool	check_cols (uint c)
virtual bool	null_inside ()
virtual void	bring_value ()
Field *	tmp_table_field_from_field_type (TABLE *table, bool fixed_length)
virtual Item_field *	field_for_view_update ()
virtual Item *	neg_transformer (THD *thd)
virtual Item *	update_value_transformer (uchar *select_arg)
virtual Item *	safe_charset_converter (const CHARSET_INFO *tocs)
void	delete_self ()
virtual bool	is_splocal ()
virtual Settable_routine_parameter *	get_settable_routine_parameter ()
bool	is_temporal_with_date () const
bool	is_temporal_with_date_and_time () const
bool	is_temporal_with_time () const
bool	is_temporal () const
bool	has_compatible_context (Item *item) const
virtual Field::geometry_type	get_geometry_type () const
String *	check_well_formed_result (String *str, bool send_error=0)
bool	eq_by_collation (Item item, bool binary_cmp, const CHARSET_INFO cs)
virtual bool	is_expensive ()
virtual bool	can_be_evaluated_now () const
uint32	max_char_length () const
void	fix_length_and_charset (uint32 max_char_length_arg, const CHARSET_INFO *cs)
void	fix_char_length (uint32 max_char_length_arg)
void	fix_char_length_ulonglong (ulonglong max_char_length_arg)
void	fix_length_and_charset_datetime (uint32 max_char_length_arg)
void	fix_length_and_dec_and_charset_datetime (uint32 max_char_length_arg, uint8 dec_arg)
virtual bool	is_outer_field () const
bool	is_blob_field () const
virtual bool	has_subquery () const
virtual bool	has_stored_program () const

Additional Inherited Members
Public Types inherited from Item_func
enum	Functype { UNKNOWN_FUNC, EQ_FUNC, EQUAL_FUNC, NE_FUNC, LT_FUNC, LE_FUNC, GE_FUNC, GT_FUNC, FT_FUNC, LIKE_FUNC, ISNULL_FUNC, ISNOTNULL_FUNC, COND_AND_FUNC, COND_OR_FUNC, XOR_FUNC, BETWEEN, IN_FUNC, MULT_EQUAL_FUNC, INTERVAL_FUNC, ISNOTNULLTEST_FUNC, SP_EQUALS_FUNC, SP_DISJOINT_FUNC, SP_INTERSECTS_FUNC, SP_TOUCHES_FUNC, SP_CROSSES_FUNC, SP_WITHIN_FUNC, SP_CONTAINS_FUNC, SP_OVERLAPS_FUNC, SP_STARTPOINT, SP_ENDPOINT, SP_EXTERIORRING, SP_POINTN, SP_GEOMETRYN, SP_INTERIORRINGN, NOT_FUNC, NOT_ALL_FUNC, NOW_FUNC, TRIG_COND_FUNC, SUSERVAR_FUNC, GUSERVAR_FUNC, COLLATE_FUNC, EXTRACT_FUNC, CHAR_TYPECAST_FUNC, FUNC_SP, UDF_FUNC, NEG_FUNC, GSYSVAR_FUNC }
enum	optimize_type { OPTIMIZE_NONE, OPTIMIZE_KEY, OPTIMIZE_OP, OPTIMIZE_NULL, OPTIMIZE_EQUAL }
Static Public Member Functions inherited from Item
static void *	operator new (size_t size) throw ()
static void *	operator new (size_t size, MEM_ROOT *mem_root) throw ()
static void	operator delete (void *ptr, size_t size)
static void	operator delete (void ptr, MEM_ROOT mem_root)
static const CHARSET_INFO *	default_charset ()
Public Attributes inherited from Item_func
uint	arg_count
Protected Member Functions inherited from Item
String *	val_string_from_real (String *str)
String *	val_string_from_int (String *str)
String *	val_string_from_decimal (String *str)
String *	val_string_from_date (String *str)
String *	val_string_from_datetime (String *str)
String *	val_string_from_time (String *str)
my_decimal *	val_decimal_from_real (my_decimal *decimal_value)
my_decimal *	val_decimal_from_int (my_decimal *decimal_value)
my_decimal *	val_decimal_from_string (my_decimal *decimal_value)
my_decimal *	val_decimal_from_date (my_decimal *decimal_value)
my_decimal *	val_decimal_from_time (my_decimal *decimal_value)
longlong	val_int_from_decimal ()
longlong	val_int_from_date ()
longlong	val_int_from_time ()
longlong	val_int_from_datetime ()
double	val_real_from_decimal ()
bool	get_date_from_string (MYSQL_TIME *ltime, uint flags)
bool	get_date_from_real (MYSQL_TIME *ltime, uint flags)
bool	get_date_from_decimal (MYSQL_TIME *ltime, uint flags)
bool	get_date_from_int (MYSQL_TIME *ltime, uint flags)
bool	get_date_from_time (MYSQL_TIME *ltime)
bool	get_date_from_numeric (MYSQL_TIME *ltime, uint fuzzydate)
bool	get_date_from_non_temporal (MYSQL_TIME *ltime, uint fuzzydate)
bool	get_time_from_string (MYSQL_TIME *ltime)
bool	get_time_from_real (MYSQL_TIME *ltime)
bool	get_time_from_decimal (MYSQL_TIME *ltime)
bool	get_time_from_int (MYSQL_TIME *ltime)
bool	get_time_from_date (MYSQL_TIME *ltime)
bool	get_time_from_datetime (MYSQL_TIME *ltime)
bool	get_time_from_numeric (MYSQL_TIME *ltime)
bool	get_time_from_non_temporal (MYSQL_TIME *ltime)
Protected Attributes inherited from Item_func
Item **	args
Item *	tmp_arg [2]
bool	const_item_cache
	Value used in calculation of result of const_item()
uint	allowed_arg_cols
table_map	used_tables_cache
	Value used in calculation of result of used_tables()
table_map	not_null_tables_cache
	Value used in calculation of result of not_null_tables()

Detailed Description

Definition at line 271 of file item_cmpfunc.h.

Member Function Documentation

void Item_in_optimizer::fix_after_pullout	(	st_select_lex *	parent_select,
		st_select_lex *	removed_select
	)

virtual

Fix after tables have been moved from one select_lex level to the parent level, e.g by semijoin conversion. Basically re-calculate all attributes dependent on the tables.

Parameters

parent_select	select_lex that tables are moved to.
removed_select	select_lex that tables are moved away from, child of parent_select.

Reimplemented from Item_func.

Definition at line 1920 of file item_cmpfunc.cc.

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Item * Item_in_optimizer::transform	(	Item_transformer	transformer,
		uchar *	argument
	)

virtual

Transform an Item_in_optimizer and its arguments with a callback function.

Parameters

transformer	the transformer callback function to be applied to the nodes of the tree of the object
parameter	to be passed to the transformer

Recursively transform the left and the right operand of this Item. The Right operand is an Item_in_subselect or its subclass. To avoid the creation of new Items, we use the fact the the left operand of the Item_in_subselect is the same as the one of 'this', so instead of transforming its operand, we just assign the left operand of the Item_in_subselect to be equal to the left operand of 'this'. The transformation is not applied further to the subquery operand if the IN predicate.

Returns

Return values

pointer	to the transformed item
NULL	if an error occurred

Reimplemented from Item_func.

Definition at line 2151 of file item_cmpfunc.cc.

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longlong Item_in_optimizer::val_int ( void )

virtual

The implementation of optimized <outer expression> [NOT] IN <subquery> predicates. It applies to predicates which have gone through the IN->EXISTS transformation in in_to_exists_transformer functions; not to subquery materialization (which has no triggered conditions).

The implementation works as follows. For the current value of the outer expression

If it contains only NULL values, the original (before rewrite by the Item_in_subselect rewrite methods) inner subquery is non-correlated and was previously executed, there is no need to re-execute it, and the previous return value is returned.

If it contains NULL values, check if there is a partial match for the inner query block by evaluating it. For clarity we repeat here the transformation previously performed on the sub-query. The expression

( oc_1, ..., oc_n ) <in predicate> ( SELECT ic_1, ..., ic_n FROM <table> WHERE <inner where> )

was transformed into

( oc_1, ..., oc_n ) <in predicate> ( SELECT ic_1, ..., ic_n FROM <table> WHERE <inner where> AND ... ( ic_k = oc_k OR ic_k IS NULL ) HAVING ... NOT ic_k IS NULL )

The evaluation will now proceed according to special rules set up elsewhere. These rules include:
- The HAVING NOT <inner column> IS NULL conditions added by the aforementioned rewrite methods will detect whether they evaluated (and rejected) a NULL value and if so, will cause the subquery to evaluate to NULL.
- The added WHERE and HAVING conditions are present only for those inner columns that correspond to outer column that are not NULL at the moment.
- If there is an eligible index for executing the subquery, the special access method "Full scan on NULL key" is employed which ensures that the inner query will detect if there are NULL values resulting from the inner query. This access method will quietly resort to table scan if it needs to find NULL values as well.
- Under these conditions, the sub-query need only be evaluated in order to find out whether it produced any rows.
  - If it did, we know that there was a partial match since there are NULL values in the outer row expression.
  - If it did not, the result is FALSE or UNKNOWN. If at least one of the HAVING sub-predicates rejected a NULL value corresponding to an outer non-NULL, and hence the inner query block returns UNKNOWN upon evaluation, there was a partial match and the result is UNKNOWN.

If it contains no NULL values, the call is forwarded to the inner query block.

See Also
Item_in_subselect::val_bool()

Item_is_not_null_test::val_int()

Implements Item.

Definition at line 2015 of file item_cmpfunc.cc.

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The documentation for this class was generated from the following files:

sql/item_cmpfunc.h
sql/item_cmpfunc.cc

Public Member Functions

Additional Inherited Members

Detailed Description

Member Function Documentation