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postgres/src/include/optimizer/pathnode.h

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Postgres95 1.01 Distribution - Virgin Sources
1996-07-09 06:22:35 +00:00
/*-------------------------------------------------------------------------
*
Change my-function-name-- to my_function_name, and optimizer renames.
1999-02-13 23:22:53 +00:00
* pathnode.h
Subselects in FROM clause, per ISO syntax: FROM (SELECT ...) [AS] alias. (Don't forget that an alias is required.) Views reimplemented as expanding to subselect-in-FROM. Grouping, aggregates, DISTINCT in views actually work now (he says optimistically). No UNION support in subselects/views yet, but I have some ideas about that. Rule-related permissions checking moved out of rewriter and into executor. INITDB REQUIRED!
2000-09-29 18:21:41 +00:00
* prototypes for pathnode.c, relnode.c.
Postgres95 1.01 Distribution - Virgin Sources
1996-07-09 06:22:35 +00:00
*
*
Tag appropriate files for rc3 Also performed an initial run through of upgrading our Copyright date to extend to 2005 ... first run here was very simple ... change everything where: grep 1996-2004 && the word 'Copyright' ... scanned through the generated list with 'less' first, and after, to make sure that I only picked up the right entries ...
2004-12-31 22:04:05 +00:00
* Portions Copyright (c) 1996-2005, 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 05:58:53 +00:00
* Portions Copyright (c) 1994, Regents of the University of California
Postgres95 1.01 Distribution - Virgin Sources
1996-07-09 06:22:35 +00:00
*
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 22:32:58 +00:00
* $PostgreSQL: pgsql/src/include/optimizer/pathnode.h,v 1.61 2005/06/05 22:32:58 tgl Exp $
Postgres95 1.01 Distribution - Virgin Sources
1996-07-09 06:22:35 +00:00
*
*-------------------------------------------------------------------------
*/
#ifndef PATHNODE_H
#define PATHNODE_H
Cleanup up include files.
1997-11-26 01:14:33 +00:00
#include "nodes/relation.h"
Replace planner's representation of relation sets, per pghackers discussion. Instead of Lists of integers, we now store variable-length bitmap sets. This should be faster as well as less error-prone.
2003-02-08 20:20:55 +00:00
Postgres95 1.01 Distribution - Virgin Sources
1996-07-09 06:22:35 +00:00
/*
* prototypes for pathnode.c
*/
New cost model for planning, incorporating a penalty for random page accesses versus sequential accesses, a (very crude) estimate of the effects of caching on random page accesses, and cost to evaluate WHERE- clause expressions. Export critical parameters for this model as SET variables. Also, create SET variables for the planner's enable flags (enable_seqscan, enable_indexscan, etc) so that these can be controlled more conveniently than via PGOPTIONS. Planner now estimates both startup cost (cost before retrieving first tuple) and total cost of each path, so it can optimize queries with LIMIT on a reasonable basis by interpolating between these costs. Same facility is a win for EXISTS(...) subqueries and some other cases. Redesign pathkey representation to achieve a major speedup in planning (I saw as much as 5X on a 10-way join); also minor changes in planner to reduce memory consumption by recycling discarded Path nodes and not constructing unnecessary lists. Minor cleanups to display more-plausible costs in some cases in EXPLAIN output. Initdb forced by change in interface to index cost estimation functions.
2000-02-15 20:49:31 +00:00
extern int compare_path_costs(Path *path1, Path *path2,
Ye-old pgindent run. Same 4-space tabs.
2000-04-12 17:17:23 +00:00
CostSelector criterion);
New cost model for planning, incorporating a penalty for random page accesses versus sequential accesses, a (very crude) estimate of the effects of caching on random page accesses, and cost to evaluate WHERE- clause expressions. Export critical parameters for this model as SET variables. Also, create SET variables for the planner's enable flags (enable_seqscan, enable_indexscan, etc) so that these can be controlled more conveniently than via PGOPTIONS. Planner now estimates both startup cost (cost before retrieving first tuple) and total cost of each path, so it can optimize queries with LIMIT on a reasonable basis by interpolating between these costs. Same facility is a win for EXISTS(...) subqueries and some other cases. Redesign pathkey representation to achieve a major speedup in planning (I saw as much as 5X on a 10-way join); also minor changes in planner to reduce memory consumption by recycling discarded Path nodes and not constructing unnecessary lists. Minor cleanups to display more-plausible costs in some cases in EXPLAIN output. Initdb forced by change in interface to index cost estimation functions.
2000-02-15 20:49:31 +00:00
extern int compare_fractional_path_costs(Path *path1, Path *path2,
Ye-old pgindent run. Same 4-space tabs.
2000-04-12 17:17:23 +00:00
double fraction);
New cost model for planning, incorporating a penalty for random page accesses versus sequential accesses, a (very crude) estimate of the effects of caching on random page accesses, and cost to evaluate WHERE- clause expressions. Export critical parameters for this model as SET variables. Also, create SET variables for the planner's enable flags (enable_seqscan, enable_indexscan, etc) so that these can be controlled more conveniently than via PGOPTIONS. Planner now estimates both startup cost (cost before retrieving first tuple) and total cost of each path, so it can optimize queries with LIMIT on a reasonable basis by interpolating between these costs. Same facility is a win for EXISTS(...) subqueries and some other cases. Redesign pathkey representation to achieve a major speedup in planning (I saw as much as 5X on a 10-way join); also minor changes in planner to reduce memory consumption by recycling discarded Path nodes and not constructing unnecessary lists. Minor cleanups to display more-plausible costs in some cases in EXPLAIN output. Initdb forced by change in interface to index cost estimation functions.
2000-02-15 20:49:31 +00:00
extern void set_cheapest(RelOptInfo *parent_rel);
Repair planning bugs caused by my misguided removal of restrictinfo link fields in JoinPaths --- turns out that we do need that after all :-(. Also, rearrange planner so that only one RelOptInfo is created for a particular set of joined base relations, no matter how many different subsets of relations it can be created from. This saves memory and processing time compared to the old method of making a bunch of RelOptInfos and then removing the duplicates. Clean up the jointree iteration logic; not sure if it's better, but I sure find it more readable and plausible now, particularly for the case of 'bushy plans'.
2000-02-07 04:41:04 +00:00
extern void add_path(RelOptInfo *parent_rel, Path *new_path);
Major planner/optimizer revision: get rid of PathOrder node type, store all ordering information in pathkeys lists (which are now lists of lists of PathKeyItem nodes, not just lists of lists of vars). This was a big win --- the code is smaller and IMHO more understandable than it was, even though it handles more cases. I believe the node changes will not force an initdb for anyone; planner nodes don't show up in stored rules.
1999-08-16 02:17:58 +00:00
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 22:32:58 +00:00
extern Path *create_seqscan_path(PlannerInfo *root, RelOptInfo *rel);
extern IndexPath *create_index_path(PlannerInfo *root,
Ye-old pgindent run. Same 4-space tabs.
2000-04-12 17:17:23 +00:00
IndexOptInfo *index,
First cut at planner support for bitmap index scans. Lots to do yet, but the code is basically working. Along the way, rewrite the entire approach to processing OR index conditions, and make it work in join cases for the first time ever. orindxpath.c is now basically obsolete, but I left it in for the time being to allow easy comparison testing against the old implementation.
2005-04-22 21:58:32 +00:00
List *clause_groups,
Planner speedup hacking. Avoid saving useless pathkeys, so that path comparison does not consider paths different when they differ only in uninteresting aspects of sort order. (We had a special case of this consideration for indexscans already, but generalize it to apply to ordered join paths too.) Be stricter about what is a canonical pathkey to allow faster pathkey comparison. Cache canonical pathkeys and dispersion stats for left and right sides of a RestrictInfo's clause, to avoid repeated computation. Total speedup will depend on number of tables in a query, but I see about 4x speedup of planning phase for a sample seven-table query.
2000-12-14 22:30:45 +00:00
List *pathkeys,
First cut at planner support for bitmap index scans. Lots to do yet, but the code is basically working. Along the way, rewrite the entire approach to processing OR index conditions, and make it work in join cases for the first time ever. orindxpath.c is now basically obsolete, but I left it in for the time being to allow easy comparison testing against the old implementation.
2005-04-22 21:58:32 +00:00
ScanDirection indexscandir,
bool isjoininner);
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 22:32:58 +00:00
extern BitmapHeapPath *create_bitmap_heap_path(PlannerInfo *root,
Create executor and planner-backend support for decoupled heap and index scans, using in-memory tuple ID bitmaps as the intermediary. The planner frontend (path creation and cost estimation) is not there yet, so none of this code can be executed. I have tested it using some hacked planner code that is far too ugly to see the light of day, however. Committing now so that the bulk of the infrastructure changes go in before the tree drifts under me.
2005-04-19 22:35:18 +00:00
RelOptInfo *rel,
First cut at planner support for bitmap index scans. Lots to do yet, but the code is basically working. Along the way, rewrite the entire approach to processing OR index conditions, and make it work in join cases for the first time ever. orindxpath.c is now basically obsolete, but I left it in for the time being to allow easy comparison testing against the old implementation.
2005-04-22 21:58:32 +00:00
Path *bitmapqual,
bool isjoininner);
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 22:32:58 +00:00
extern BitmapAndPath *create_bitmap_and_path(PlannerInfo *root,
Rethink original decision to use AND/OR Expr nodes to represent bitmap logic operations during planning. Seems cleaner to create two new Path node types, instead --- this avoids duplication of cost-estimation code. Also, create an enable_bitmapscan GUC parameter to control use of bitmap plans.
2005-04-21 19:18:13 +00:00
RelOptInfo *rel,
List *bitmapquals);
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 22:32:58 +00:00
extern BitmapOrPath *create_bitmap_or_path(PlannerInfo *root,
Rethink original decision to use AND/OR Expr nodes to represent bitmap logic operations during planning. Seems cleaner to create two new Path node types, instead --- this avoids duplication of cost-estimation code. Also, create an enable_bitmapscan GUC parameter to control use of bitmap plans.
2005-04-21 19:18:13 +00:00
RelOptInfo *rel,
List *bitmapquals);
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 22:32:58 +00:00
extern TidPath *create_tidscan_path(PlannerInfo *root, RelOptInfo *rel,
pgindent run on all C files. Java run to follow. initdb/regression tests pass.
2001-10-25 05:50:21 +00:00
List *tideval);
Restructure handling of inheritance queries so that they work with outer joins, and clean things up a good deal at the same time. Append plan node no longer hacks on rangetable at runtime --- instead, all child tables are given their own RT entries during planning. Concept of multiple target tables pushed up into execMain, replacing bug-prone implementation within nodeAppend. Planner now supports generating Append plans for inheritance sets either at the top of the plan (the old way) or at the bottom. Expanding at the bottom is appropriate for tables used as sources, since they may appear inside an outer join; but we must still expand at the top when the target of an UPDATE or DELETE is an inheritance set, because we actually need a different targetlist and junkfilter for each target table in that case. Fortunately a target table can't be inside an outer join... Bizarre mutual recursion between union_planner and prepunion.c is gone --- in fact, union_planner doesn't really have much to do with union queries anymore, so I renamed it grouping_planner.
2000-11-12 00:37:02 +00:00
extern AppendPath *create_append_path(RelOptInfo *rel, List *subpaths);
First phase of implementing hash-based grouping/aggregation. An AGG plan node now does its own grouping of the input rows, and has no need for a preceding GROUP node in the plan pipeline. This allows elimination of the misnamed tuplePerGroup option for GROUP, and actually saves more code in nodeGroup.c than it costs in nodeAgg.c, as well as being presumably faster. Restructure the API of query_planner so that we do not commit to using a sorted or unsorted plan in query_planner; instead grouping_planner makes the decision. (Right now it isn't any smarter than query_planner was, but that will change as soon as it has the option to select a hash- based aggregation step.) Despite all the hackery, no initdb needed since only in-memory node types changed.
2002-11-06 00:00:45 +00:00
extern ResultPath *create_result_path(RelOptInfo *rel, Path *subpath,
pgindent run.
2003-08-04 00:43:34 +00:00
List *constantqual);
Be more realistic about plans involving Materialize nodes: take their cost into account while planning.
2002-11-30 05:21:03 +00:00
extern MaterialPath *create_material_path(RelOptInfo *rel, Path *subpath);
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 22:32:58 +00:00
extern UniquePath *create_unique_path(PlannerInfo *root, RelOptInfo *rel,
pgindent run.
2003-08-04 00:43:34 +00:00
Path *subpath);
Teach planner how to propagate pathkeys from sub-SELECTs in FROM up to the outer query. (The implementation is a bit klugy, but it would take nontrivial restructuring to make it nicer, which this is probably not worth.) This avoids unnecessary sort steps in examples like SELECT foo,count(*) FROM (SELECT ... ORDER BY foo,bar) sub GROUP BY foo which means there is now a reasonable technique for controlling the order of inputs to custom aggregates, even in the grouping case.
2003-02-15 20:12:41 +00:00
extern Path *create_subqueryscan_path(RelOptInfo *rel, List *pathkeys);
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 22:32:58 +00:00
extern Path *create_functionscan_path(PlannerInfo *root, RelOptInfo *rel);
Major planner/optimizer revision: get rid of PathOrder node type, store all ordering information in pathkeys lists (which are now lists of lists of PathKeyItem nodes, not just lists of lists of vars). This was a big win --- the code is smaller and IMHO more understandable than it was, even though it handles more cases. I believe the node changes will not force an initdb for anyone; planner nodes don't show up in stored rules.
1999-08-16 02:17:58 +00:00
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 22:32:58 +00:00
extern NestPath *create_nestloop_path(PlannerInfo *root,
pgindent run on all C files. Java run to follow. initdb/regression tests pass.
2001-10-25 05:50:21 +00:00
RelOptInfo *joinrel,
JoinType jointype,
Path *outer_path,
Path *inner_path,
List *restrict_clauses,
List *pathkeys);
Another round of planner/optimizer work. This is just restructuring and code cleanup; no major improvements yet. However, EXPLAIN does produce more intuitive outputs for nested loops with indexscans now...
2000-01-09 00:26:47 +00:00
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 22:32:58 +00:00
extern MergePath *create_mergejoin_path(PlannerInfo *root,
pgindent run on all C files. Java run to follow. initdb/regression tests pass.
2001-10-25 05:50:21 +00:00
RelOptInfo *joinrel,
JoinType jointype,
Path *outer_path,
Path *inner_path,
List *restrict_clauses,
List *pathkeys,
List *mergeclauses,
List *outersortkeys,
List *innersortkeys);
Another round of planner/optimizer work. This is just restructuring and code cleanup; no major improvements yet. However, EXPLAIN does produce more intuitive outputs for nested loops with indexscans now...
2000-01-09 00:26:47 +00:00
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 22:32:58 +00:00
extern HashPath *create_hashjoin_path(PlannerInfo *root,
pgindent run on all C files. Java run to follow. initdb/regression tests pass.
2001-10-25 05:50:21 +00:00
RelOptInfo *joinrel,
JoinType jointype,
Path *outer_path,
Path *inner_path,
List *restrict_clauses,
List *hashclauses);
Postgres95 1.01 Distribution - Virgin Sources
1996-07-09 06:22:35 +00:00
/*
Repair planning bugs caused by my misguided removal of restrictinfo link fields in JoinPaths --- turns out that we do need that after all :-(. Also, rearrange planner so that only one RelOptInfo is created for a particular set of joined base relations, no matter how many different subsets of relations it can be created from. This saves memory and processing time compared to the old method of making a bunch of RelOptInfos and then removing the duplicates. Clean up the jointree iteration logic; not sure if it's better, but I sure find it more readable and plausible now, particularly for the case of 'bushy plans'.
2000-02-07 04:41:04 +00:00
* prototypes for relnode.c
Postgres95 1.01 Distribution - Virgin Sources
1996-07-09 06:22:35 +00:00
*/
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 22:32:58 +00:00
extern void build_base_rel(PlannerInfo *root, int relid);
extern RelOptInfo *build_other_rel(PlannerInfo *root, int relid);
extern RelOptInfo *find_base_rel(PlannerInfo *root, int relid);
extern RelOptInfo *find_join_rel(PlannerInfo *root, Relids relids);
extern RelOptInfo *build_join_rel(PlannerInfo *root,
pgindent run.
2003-08-04 00:43:34 +00:00
Relids joinrelids,
RelOptInfo *outer_rel,
RelOptInfo *inner_rel,
JoinType jointype,
List **restrictlist_ptr);
Another pgindent run. Fixes enum indenting, and improves #endif spacing. Also adds space for one-line comments.
2001-10-28 06:26:15 +00:00
New pgindent run with fixes suggested by Tom. Patch manually reviewed, initdb/regression tests pass.
2001-11-05 17:46:40 +00:00
#endif /* PATHNODE_H */
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