MySQL 8.0.31
Source Code Documentation
pars0opt.h File Reference

Simple SQL optimizer. More...

#include "dict0types.h"
#include "pars0sym.h"
#include "que0types.h"
#include "row0sel.h"
#include "univ.i"
#include "usr0types.h"

Go to the source code of this file.

Functions

void opt_search_plan (sel_node_t *sel_node)
 Optimizes a select. More...
 
void opt_find_all_cols (bool copy_val, dict_index_t *index, sym_node_list_t *col_list, plan_t *plan, que_node_t *exp)
 Looks for occurrences of the columns of the table in the query subgraph and adds them to the list of columns if an occurrence of the same column does not already exist in the list. More...
 

Detailed Description

Simple SQL optimizer.

Created 12/21/1997 Heikki Tuuri

Function Documentation

◆ opt_find_all_cols()

void opt_find_all_cols ( bool  copy_val,
dict_index_t index,
sym_node_list_t *  col_list,
plan_t plan,
que_node_t exp 
)

Looks for occurrences of the columns of the table in the query subgraph and adds them to the list of columns if an occurrence of the same column does not already exist in the list.

If the column is already in the list, puts a value indirection to point to the occurrence in the column list, except if the column occurrence we are looking at is in the column list, in which case nothing is done. in: expression or condition

If the column is already in the list, puts a value indirection to point to the occurrence in the column list, except if the column occurrence we are looking at is in the column list, in which case nothing is done.

Parameters
copy_valin: if true, new found columns are added as columns to copy
indexin: index of the table to use
col_listin: base node of a list where to add new found columns
planin: plan or NULL
expin: expression or condition or NULL

◆ opt_search_plan()

void opt_search_plan ( sel_node_t sel_node)

Optimizes a select.

Decides which indexes to tables to use. The tables are accessed in the order that they were written to the FROM part in the select statement. in: parsed select node

Decides which indexes to tables to use. The tables are accessed in the order that they were written to the FROM part in the select statement.

Parameters
sel_nodein: parsed select node