database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-10-28 11:55:03 +03:00
Code Activity

IN clauses appearing at top level of WHERE can now be handled as joins.

Browse Source 
There are two implementation techniques: the executor understands a new
JOIN_IN jointype, which emits at most one matching row per left-hand row,
or the result of the IN's sub-select can be fed through a DISTINCT filter
and then joined as an ordinary relation.
Along the way, some minor code cleanup in the optimizer; notably, break
out most of the jointree-rearrangement preprocessing in planner.c and
put it in a new file prep/prepjointree.c.
This commit is contained in:
Tom Lane
2003-01-20 18:55:07 +00:00
parent be2b660ecd
commit bdfbfde1b1
47 changed files with 2075 additions and 875 deletions
Download Patch File Download Diff File Expand all files Collapse all files

8
src/include/optimizer/subselect.h
View File

@@ -2,6 +2,11 @@
*
* subselect.h
*
* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $Id: subselect.h,v 1.17 2003/01/20 18:55:05 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#ifndef SUBSELECT_H
@@ -14,8 +19,9 @@ extern List *PlannerInitPlan; /* init subplans for current query */
extern List *PlannerParamVar; /* to get Var from Param->paramid */
extern int PlannerPlanId; /* to assign unique ID to subquery plans */
extern List *SS_finalize_plan(Plan *plan, List *rtable);
extern Node *convert_IN_to_join(Query *parse, SubLink *sublink);
extern Node *SS_replace_correlation_vars(Node *expr);
extern Node *SS_process_sublinks(Node *expr, bool isQual);
extern List *SS_finalize_plan(Plan *plan, List *rtable);
#endif /* SUBSELECT_H */