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_val	in: if true, new found columns are added as columns to copy
index	in: index of the table to use
col_list	in: base node of a list where to add new found columns
plan	in: plan or NULL
exp	in: 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_node

in: parsed select node