postgresql/src/include/optimizer/joininfo.h

/*-------------------------------------------------------------------------
 *
 * joininfo.h
 *	  prototypes for joininfo.c.
 *
 *
 * Portions Copyright (c) 1996-2022, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * src/include/optimizer/joininfo.h
 *
 *-------------------------------------------------------------------------
 */
#ifndef JOININFO_H
#define JOININFO_H

#include "nodes/pathnodes.h"


extern bool have_relevant_joinclause(PlannerInfo *root,
									 RelOptInfo *rel1, RelOptInfo *rel2);

extern void add_join_clause_to_rels(PlannerInfo *root,
									RestrictInfo *restrictinfo,
									Relids join_relids);
extern void remove_join_clause_from_rels(PlannerInfo *root,
										 RestrictInfo *restrictinfo,
										 Relids join_relids);

#endif							/* JOININFO_H */
Postgres95 1.01 Distribution - Virgin Sources 1996-07-09 02:22:35 -04:00			`/*-------------------------------------------------------------------------`
			`*`
Change my-function-name-- to my_function_name, and optimizer renames. 1999-02-13 18:22:53 -05:00			`* joininfo.h`
Postgres95 1.01 Distribution - Virgin Sources 1996-07-09 02:22:35 -04:00			`* prototypes for joininfo.c.`
			`*`
			`*`
Update copyright for 2022 Backpatch-through: 10 2022-01-07 19:04:57 -05:00			`* Portions Copyright (c) 1996-2022, PostgreSQL Global Development Group`
Add: * Portions Copyright (c) 1996-2000, PostgreSQL, Inc to all files copyright Regents of Berkeley. Man, that's a lot of files. 2000-01-26 00:58:53 -05:00			`* Portions Copyright (c) 1994, Regents of the University of California`
Postgres95 1.01 Distribution - Virgin Sources 1996-07-09 02:22:35 -04:00			`*`
Remove cvs keywords from all files. 2010-09-20 16:08:53 -04:00			`* src/include/optimizer/joininfo.h`
Postgres95 1.01 Distribution - Virgin Sources 1996-07-09 02:22:35 -04:00			`*`
			`*-------------------------------------------------------------------------`
			`*/`
			`#ifndef JOININFO_H`
			`#define JOININFO_H`

Rename nodes/relation.h to nodes/pathnodes.h. The old name of this file was never a very good indication of what it was for. Now that there's also access/relation.h, we have a potential confusion hazard as well, so let's rename it to something more apropos. Per discussion, "pathnodes.h" is reasonable, since a good fraction of the file is Path node definitions. While at it, tweak a couple of other headers that were gratuitously importing relation.h into modules that don't need it. Discussion: https://postgr.es/m/7719.1548688728@sss.pgh.pa.us 2019-01-29 16:49:25 -05:00			`#include "nodes/pathnodes.h"`
Cleanup up include files. 1997-11-25 20:14:33 -05:00
Modify planner's implied-equality-deduction code so that when a set of known-equal expressions includes any constant expressions (including Params from outer queries), we actively suppress any 'var = var' clauses that are or could be deduced from the set, generating only the deducible 'var = const' clauses instead. The idea here is to push down the restrictions implied by the equality set to base relations whenever possible. Once we have applied the 'var = const' clauses, the 'var = var' clauses are redundant, and should be suppressed both to save work at execution and to avoid double-counting restrictivity. 2003-01-23 22:58:44 -05:00
Fix planner to do the right thing when a degenerate outer join (one whose joinclause doesn't use any outer-side vars) requires a "bushy" plan to be created. The normal heuristic to avoid joins with no joinclause has to be overridden in that case. Problem is new in 8.2; before that we forced the outer join order anyway. Per example from Teodor. 2006-12-12 16:31:02 -05:00			`extern bool have_relevant_joinclause(PlannerInfo *root,`
			`RelOptInfo rel1, RelOptInfo rel2);`
Modify planner's implied-equality-deduction code so that when a set of known-equal expressions includes any constant expressions (including Params from outer queries), we actively suppress any 'var = var' clauses that are or could be deduced from the set, generating only the deducible 'var = const' clauses instead. The idea here is to push down the restrictions implied by the equality set to base relations whenever possible. Once we have applied the 'var = const' clauses, the 'var = var' clauses are redundant, and should be suppressed both to save work at execution and to avoid double-counting restrictivity. 2003-01-23 22:58:44 -05:00
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. 2005-06-05 18:32:58 -04:00			`extern void add_join_clause_to_rels(PlannerInfo *root,`
Modify planner's implied-equality-deduction code so that when a set of known-equal expressions includes any constant expressions (including Params from outer queries), we actively suppress any 'var = var' clauses that are or could be deduced from the set, generating only the deducible 'var = const' clauses instead. The idea here is to push down the restrictions implied by the equality set to base relations whenever possible. Once we have applied the 'var = const' clauses, the 'var = var' clauses are redundant, and should be suppressed both to save work at execution and to avoid double-counting restrictivity. 2003-01-23 22:58:44 -05:00			`RestrictInfo *restrictinfo,`
			`Relids join_relids);`
Fix join-removal logic for pseudoconstant and outerjoin-delayed quals. In these cases a qual can get marked with the removable rel in its required_relids, but this is just to schedule its evaluation correctly, not because it really depends on the rel. We were assuming that, in effect, we could throw away all quals so marked, which is nonsense. Tighten up the logic to be a little more paranoid about which quals belong to the outer join being considered for removal, and arrange for all quals that don't belong to be updated so they will still get evaluated correctly. Also fix another problem that happened to be exposed by this test case, which was that make_join_rel() was failing to notice some cases where a constant-false qual could be used to prove a join relation empty. If it's a pushed-down constant false, then the relation is empty even if it's an outer join, because the qual applies after the outer join expansion. Per report from Nathan Grange. Back-patch into 9.0. 2010-09-14 19:15:29 -04:00			`extern void remove_join_clause_from_rels(PlannerInfo *root,`
			`RestrictInfo *restrictinfo,`
			`Relids join_relids);`
Another pgindent run. Fixes enum indenting, and improves #endif spacing. Also adds space for one-line comments. 2001-10-28 01:26:15 -05:00
Postgres95 1.01 Distribution - Virgin Sources 1996-07-09 02:22:35 -04:00			`#endif /* JOININFO_H */`