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postgresql/src/include/optimizer/subselect.h

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Subselects...
1998-02-12 22:46:56 -05:00
/*-------------------------------------------------------------------------
*
Change my-function-name-- to my_function_name, and optimizer renames.
1999-02-13 18:22:53 -05:00
* subselect.h
Subselects...
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*
Update copyrights in source tree to 2008.
2008-01-01 14:46:01 -05:00
* Portions Copyright (c) 1996-2008, 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.
2003-01-20 13:55:07 -05:00
* Portions Copyright (c) 1994, Regents of the University of California
*
Improve sublink pullup code to handle ANY/EXISTS sublinks that are at top level of a JOIN/ON clause, not only at top level of WHERE. (However, we can't do this in an outer join's ON clause, unless the ANY/EXISTS refers only to the nullable side of the outer join, so that it can effectively be pushed down into the nullable side.) Per request from Kevin Grittner. In passing, fix a bug in the initial implementation of EXISTS pullup: it would Assert if the EXIST's WHERE clause used a join alias variable. Since we haven't yet flattened join aliases when this transformation happens, it's necessary to include join relids in the computed set of RHS relids.
2008-08-16 21:20:00 -04:00
* $PostgreSQL: pgsql/src/include/optimizer/subselect.h,v 1.33 2008/08/17 01:20:00 tgl 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.
2003-01-20 13:55:07 -05:00
*
Subselects...
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*-------------------------------------------------------------------------
*/
#ifndef SUBSELECT_H
#define SUBSELECT_H
Cleanup of /include #include's, for 6.6 only.
1999-07-13 21:20:30 -04:00
#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.
2005-06-05 18:32:58 -04:00
#include "nodes/relation.h"
Improve sublink pullup code to handle ANY/EXISTS sublinks that are at top level of a JOIN/ON clause, not only at top level of WHERE. (However, we can't do this in an outer join's ON clause, unless the ANY/EXISTS refers only to the nullable side of the outer join, so that it can effectively be pushed down into the nullable side.) Per request from Kevin Grittner. In passing, fix a bug in the initial implementation of EXISTS pullup: it would Assert if the EXIST's WHERE clause used a join alias variable. Since we haven't yet flattened join aliases when this transformation happens, it's necessary to include join relids in the computed set of RHS relids.
2008-08-16 21:20:00 -04:00
extern bool convert_ANY_sublink_to_join(PlannerInfo *root, SubLink *sublink,
Relids available_rels,
Node **new_qual, List **fromlist);
extern bool convert_EXISTS_sublink_to_join(PlannerInfo *root, SubLink *sublink,
bool under_not,
Relids available_rels,
Node **new_qual, List **fromlist);
Get rid of some old and crufty global variables in the planner. When this code was last gone over, there wasn't really any alternative to globals because we didn't have the PlannerInfo struct being passed all through the planner code. Now that we do, we can restructure things to avoid non-reentrancy. I'm fooling with this because otherwise I'd have had to add another global variable for the planned compact range table list.
2007-02-19 02:03:34 -05:00
extern Node *SS_replace_correlation_vars(PlannerInfo *root, Node *expr);
extern Node *SS_process_sublinks(PlannerInfo *root, Node *expr, bool isQual);
Tighten up SS_finalize_plan's computation of valid_params to exclude Params of the current query level that aren't in fact output parameters of the current initPlans. (This means, for example, output parameters of regular subplans.) To make this work correctly for output parameters coming from sibling initplans requires rejiggering the API of SS_finalize_plan just a bit: we need the siblings to be visible to it, rather than hidden as SS_make_initplan_from_plan had been doing. This is really part of my response to bug #4290, but I concluded this part probably shouldn't be back-patched, since all that it's doing is to make a debugging cross-check tighter.
2008-07-09 22:14:03 -04:00
extern void SS_finalize_plan(PlannerInfo *root, Plan *plan,
bool attach_initplans);
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 Param *SS_make_initplan_from_plan(PlannerInfo *root, Plan *plan,
Standard pgindent run for 8.1.
2005-10-14 22:49:52 -04:00
Oid resulttype, int32 resulttypmod);
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
New pgindent run with fixes suggested by Tom. Patch manually reviewed, initdb/regression tests pass.
2001-11-05 12:46:40 -05:00
#endif /* SUBSELECT_H */
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