MySQL 8.4.3
Source Code Documentation
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Fold constant query expressions. More...
#include "sql/sql_const_folding.h"
#include <assert.h>
#include <float.h>
#include <stdint.h>
#include <sys/types.h>
#include <utility>
#include "decimal.h"
#include "field_types.h"
#include "my_inttypes.h"
#include "my_time.h"
#include "mysql/strings/dtoa.h"
#include "mysql/udf_registration_types.h"
#include "mysql_time.h"
#include "sql-common/my_decimal.h"
#include "sql/field.h"
#include "sql/item.h"
#include "sql/item_cmpfunc.h"
#include "sql/item_func.h"
#include "sql/item_timefunc.h"
#include "sql/sql_class.h"
#include "sql/sql_list.h"
#include "sql/sql_time.h"
#include "sql/tztime.h"
#include "sql_string.h"
#include "template_utils.h"
Enumerations | |
enum | Range_placement { RP_OUTSIDE_HIGH , RP_OUTSIDE_LOW , RP_ON_MIN , RP_ON_MAX , RP_INSIDE , RP_INSIDE_TRUNCATED , RP_INSIDE_YEAR_HOLE , RP_ROUNDED_DOWN , RP_ROUNDED_UP } |
fold_condition uses analyze_field_constant to analyze constants in comparisons expressions with a view to fold the expression. More... | |
Functions | |
static bool | round_fold_or_convert_dec (THD *thd, Item **const_val, Range_placement *place, Item_field *f, my_decimal *d, bool up, bool *discount_equal) |
Minion of analyze_int_field_constant. More... | |
static bool | fold_or_convert_dec (THD *thd, Item **const_val, Range_placement *place, Item_field *f, my_decimal *d) |
Minion of analyze_int_field_constant. More... | |
static bool | analyze_int_field_constant (THD *thd, Item_field *f, Item **const_val, Item_func::Functype ft, bool left_has_field, Range_placement *place, bool *discount_equal) |
Minion of analyze_field_constant for integer type fields. More... | |
static bool | analyze_decimal_field_constant (THD *thd, const Item_field *f, Item **const_val, Item_func::Functype ft, Range_placement *place, bool *negative) |
Minion of analyze_field_constant for decimal type fields. More... | |
static bool | analyze_real_field_constant (THD *thd, Item_field *f, Item **const_val, Range_placement *place) |
Minion of analyze_field_constant for real type fields. More... | |
static bool | analyze_year_field_constant (THD *thd, Item **const_val, Range_placement *place) |
Minion of analyze_field_constant for YEAR type fields. More... | |
static bool | analyze_timestamp_field_constant (THD *thd, const Item_field *f, Item **const_val, Range_placement *place) |
Minion of analyze_field_constant for TIMESTAMP, DATETIME, DATE fields. More... | |
static bool | analyze_time_field_constant (THD *thd, Item **const_val) |
static bool | analyze_field_constant (THD *thd, Item_field *f, Item **const_val, Item_func *func, bool left_has_field, Range_placement *place, bool *discount_equal, bool *negative) |
Analyze a constant's placement within (or without) the type range of the field f. More... | |
static bool | fold_or_simplify (THD *thd, Item *ref_or_field, Item_func::Functype ft, bool always_true, bool manifest_result, Item **retcond, Item::cond_result *cond_value) |
We have found that the constant's value makes the predicate always true or false (modulo field nullability), so simplify or remove the condition according to this table: More... | |
static bool | fold_arguments (THD *thd, Item_func *func) |
static bool | fold_arguments (THD *thd, Item_cond *cond) |
Call fold_condition on all the conditions's arguments. More... | |
static Range_placement | map_less_to_greater (Range_placement place) |
Switch places of low, high, max and min. More... | |
static bool | adjust_cmp_op (THD *thd, Item_func *func, bool left_has_field, bool inverse, Item *ref_or_field, Item *c, Item **retcond) |
Possibly change comparison operator because we have rounded the constant in some direction. More... | |
static bool | simplify_to_equal (THD *thd, Item *ref_or_field, Item *c, Item **retcond, Item::cond_result *cond_value) |
Replace condition in retcond with "=" (i.e. Item_func_eq) and set cond_value to Item::COND_OK. More... | |
bool | fold_condition (THD *thd, Item *cond, Item **retcond, Item::cond_result *cond_value, bool manifest_result) |
Fold boolean condition {=, <>, >, >=, <, <=, <=>} involving constants and fields (or references to fields), possibly determining if the condition is always true or false based on type range of the field, or possibly simplifying >=, <= to = if constant lies on the range border. More... | |
Fold constant query expressions.
Currently, this is only done at optimize time, but should eventually be done as much as possible at prepare time. For dynamic parameters, we'd still need to do it at optimize time.