postgres/src/include/optimizer/subselect.h

/*-------------------------------------------------------------------------
 *
 * subselect.h
 *
 * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * $PostgreSQL: pgsql/src/include/optimizer/subselect.h,v 1.27 2006/03/05 15:58:57 momjian Exp $
 *
 *-------------------------------------------------------------------------
 */
#ifndef SUBSELECT_H
#define SUBSELECT_H

#include "nodes/plannodes.h"
#include "nodes/relation.h"


extern Index PlannerQueryLevel; /* level of current query */
extern List *PlannerInitPlan;	/* init subplans for current query */
extern List *PlannerParamList;	/* to keep track of cross-level Params */
extern int	PlannerPlanId;		/* to assign unique ID to subquery plans */

extern Node *convert_IN_to_join(PlannerInfo *root, SubLink *sublink);
extern Node *SS_replace_correlation_vars(Node *expr);
extern Node *SS_process_sublinks(Node *expr, bool isQual);
extern void SS_finalize_plan(Plan *plan, List *rtable);
extern Param *SS_make_initplan_from_plan(PlannerInfo *root, Plan *plan,
						   Oid resulttype, int32 resulttypmod);

#endif   /* SUBSELECT_H */
Subselects... 28 years ago			`/*-------------------------------------------------------------------------`
			`*`
Change my-function-name-- to my_function_name, and optimizer renames. 27 years ago			`* subselect.h`
Subselects... 28 years ago			`*`
Update copyright for 2006. Update scripts. 20 years ago			`* Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group`
IN clauses appearing at top level of WHERE can now be handled as joins. 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. 23 years ago			`* Portions Copyright (c) 1994, Regents of the University of California`
			`*`
Update copyright for 2006. Update scripts. 20 years ago			`* $PostgreSQL: pgsql/src/include/optimizer/subselect.h,v 1.27 2006/03/05 15:58:57 momjian Exp $`
IN clauses appearing at top level of WHERE can now be handled as joins. 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. 23 years ago			`*`
Subselects... 28 years ago			`*-------------------------------------------------------------------------`
			`*/`
			`#ifndef SUBSELECT_H`
			`#define SUBSELECT_H`

Cleanup of /include #include's, for 6.6 only. 27 years ago			`#include "nodes/plannodes.h"`
Remove planner's private fields from Query struct, and put them into a new PlannerInfo struct, which is passed around instead of the bare Query in all the planning code. This commit is essentially just a code-beautification exercise, but it does open the door to making larger changes to the planner data structures without having to muck with the widely-known Query struct. 21 years ago			`#include "nodes/relation.h"`

Cleanup of /include #include's, for 6.6 only. 27 years ago
Ye-old pgindent run. Same 4-space tabs. 26 years ago			`extern Index PlannerQueryLevel; /* level of current query */`
pgindent run before 6.3 release, with Thomas' requested changes. 28 years ago			`extern List PlannerInitPlan; / init subplans for current query */`
Implement outer-level aggregates to conform to the SQL spec, with extensions to support our historical behavior. An aggregate belongs to the closest query level of any of the variables in its argument, or the current query level if there are no variables (e.g., COUNT(*)). The implementation involves adding an agglevelsup field to Aggref, and treating outer aggregates like outer variables at planning time. 23 years ago			`extern List PlannerParamList; / to keep track of cross-level Params */`
Clean up problems with sublinks + grouping in planner. Not sure if they are all fixed, because rewriter is now the stumbling block, but at least some cases work that did not work before. 27 years ago			`extern int PlannerPlanId; /* to assign unique ID to subquery plans */`
Subselects... 28 years ago
Remove planner's private fields from Query struct, and put them into a new PlannerInfo struct, which is passed around instead of the bare Query in all the planning code. This commit is essentially just a code-beautification exercise, but it does open the door to making larger changes to the planner data structures without having to muck with the widely-known Query struct. 21 years ago			`extern Node convert_IN_to_join(PlannerInfo root, SubLink *sublink);`
pgindent run before 6.3 release, with Thomas' requested changes. 28 years ago			`extern Node SS_replace_correlation_vars(Node expr);`
Reconsider mechanism for marking sub-selects that are at top level of a qualification clause (and hence can get away with being sloppy about distinguishing FALSE from UNKNOWN). We need to know this in subselect.c; marking the subplans in setrefs.c is too late. 23 years ago			`extern Node SS_process_sublinks(Node expr, bool isQual);`
Make further use of new bitmapset code: executor's chgParam, extParam, locParam lists can be converted to bitmapsets to speed updating. Also, replace 'locParam' with 'allParam', which contains all the paramIDs relevant to the node (i.e., the union of extParam and locParam); this saves a step during SetChangedParamList() without costing anything elsewhere. 23 years ago			`extern void SS_finalize_plan(Plan plan, List rtable);`
Remove planner's private fields from Query struct, and put them into a new PlannerInfo struct, which is passed around instead of the bare Query in all the planning code. This commit is essentially just a code-beautification exercise, but it does open the door to making larger changes to the planner data structures without having to muck with the widely-known Query struct. 21 years ago			`extern Param SS_make_initplan_from_plan(PlannerInfo root, Plan *plan,`
Standard pgindent run for 8.1. 21 years ago			`Oid resulttype, int32 resulttypmod);`
Another pgindent run. Fixes enum indenting, and improves #endif spacing. Also adds space for one-line comments. 25 years ago
New pgindent run with fixes suggested by Tom. Patch manually reviewed, initdb/regression tests pass. 25 years ago			`#endif /* SUBSELECT_H */`