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postgresql/src/include/utils/selfuncs.h

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Optimizer can now estimate selectivity of IS NULL, IS NOT NULL, IS TRUE, etc, with some degree of verisimilitude. Split out selectivity support functions from builtins.h into a new header file selfuncs.h, so as to reduce the number of header files builtins.h must depend on. Fix a few missing inclusions exposed thereby. From Joe Conway, with some kibitzing from Tom Lane.
2001-06-25 23:11:45 +02:00
/*-------------------------------------------------------------------------
*
* selfuncs.h
* Selectivity functions and index cost estimation functions for
* standard operators and index access methods.
*
*
Update copyright for 2015 Backpatch certain files through 9.0
2015-01-06 17:43:47 +01:00
* Portions Copyright (c) 1996-2015, PostgreSQL Global Development Group
Optimizer can now estimate selectivity of IS NULL, IS NOT NULL, IS TRUE, etc, with some degree of verisimilitude. Split out selectivity support functions from builtins.h into a new header file selfuncs.h, so as to reduce the number of header files builtins.h must depend on. Fix a few missing inclusions exposed thereby. From Joe Conway, with some kibitzing from Tom Lane.
2001-06-25 23:11:45 +02:00
* Portions Copyright (c) 1994, Regents of the University of California
*
Remove cvs keywords from all files.
2010-09-20 22:08:53 +02:00
* src/include/utils/selfuncs.h
Optimizer can now estimate selectivity of IS NULL, IS NOT NULL, IS TRUE, etc, with some degree of verisimilitude. Split out selectivity support functions from builtins.h into a new header file selfuncs.h, so as to reduce the number of header files builtins.h must depend on. Fix a few missing inclusions exposed thereby. From Joe Conway, with some kibitzing from Tom Lane.
2001-06-25 23:11:45 +02:00
*
*-------------------------------------------------------------------------
*/
#ifndef SELFUNCS_H
#define SELFUNCS_H
#include "fmgr.h"
Move ltree parentsel() selectivity function into /contrib/ltree.
2006-04-27 00:33:36 +02:00
#include "access/htup.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.
2005-06-06 00:32:58 +02:00
#include "nodes/relation.h"
Optimizer can now estimate selectivity of IS NULL, IS NOT NULL, IS TRUE, etc, with some degree of verisimilitude. Split out selectivity support functions from builtins.h into a new header file selfuncs.h, so as to reduce the number of header files builtins.h must depend on. Fix a few missing inclusions exposed thereby. From Joe Conway, with some kibitzing from Tom Lane.
2001-06-25 23:11:45 +02:00
Use a hopefully-more-reliable method of detecting default selectivity estimates when combining the estimates for a range query. As pointed out by Miquel van Smoorenburg, the existing check for an impossible combined result would quite possibly fail to detect one default and one non-default input. It seems better to use the default range query estimate in such cases. To do so, add a check for an estimate of exactly DEFAULT_INEQ_SEL. This is a bit ugly because it introduces additional coupling between clauselist_selectivity and scalarltsel/scalargtsel, but it's not like there wasn't plenty already...
2004-11-09 01:34:46 +01:00
/*
* Note: the default selectivity estimates are not chosen entirely at random.
* We want them to be small enough to ensure that indexscans will be used if
pgindent run for 9.4 This includes removing tabs after periods in C comments, which was applied to back branches, so this change should not effect backpatching.
2014-05-06 18:12:18 +02:00
* available, for typical table densities of ~100 tuples/page. Thus, for
Use a hopefully-more-reliable method of detecting default selectivity estimates when combining the estimates for a range query. As pointed out by Miquel van Smoorenburg, the existing check for an impossible combined result would quite possibly fail to detect one default and one non-default input. It seems better to use the default range query estimate in such cases. To do so, add a check for an estimate of exactly DEFAULT_INEQ_SEL. This is a bit ugly because it introduces additional coupling between clauselist_selectivity and scalarltsel/scalargtsel, but it's not like there wasn't plenty already...
2004-11-09 01:34:46 +01:00
* example, 0.01 is not quite small enough, since that makes it appear that
* nearly all pages will be hit anyway. Also, since we sometimes estimate
* eqsel as 1/num_distinct, we probably want DEFAULT_NUM_DISTINCT to equal
* 1/DEFAULT_EQ_SEL.
*/
/* default selectivity estimate for equalities such as "A = b" */
#define DEFAULT_EQ_SEL 0.005
/* default selectivity estimate for inequalities such as "A < b" */
#define DEFAULT_INEQ_SEL 0.3333333333333333
/* default selectivity estimate for range inequalities "A > b AND A < c" */
Standard pgindent run for 8.1.
2005-10-15 04:49:52 +02:00
#define DEFAULT_RANGE_INEQ_SEL 0.005
Use a hopefully-more-reliable method of detecting default selectivity estimates when combining the estimates for a range query. As pointed out by Miquel van Smoorenburg, the existing check for an impossible combined result would quite possibly fail to detect one default and one non-default input. It seems better to use the default range query estimate in such cases. To do so, add a check for an estimate of exactly DEFAULT_INEQ_SEL. This is a bit ugly because it introduces additional coupling between clauselist_selectivity and scalarltsel/scalargtsel, but it's not like there wasn't plenty already...
2004-11-09 01:34:46 +01:00
/* default selectivity estimate for pattern-match operators such as LIKE */
#define DEFAULT_MATCH_SEL 0.005
/* default number of distinct values in a table */
#define DEFAULT_NUM_DISTINCT 200
/* default selectivity estimate for boolean and null test nodes */
#define DEFAULT_UNK_SEL 0.005
#define DEFAULT_NOT_UNK_SEL (1.0 - DEFAULT_UNK_SEL)
/*
* Clamp a computed probability estimate (which may suffer from roundoff or
* estimation errors) to valid range. Argument must be a float variable.
*/
#define CLAMP_PROBABILITY(p) \
do { \
if (p < 0.0) \
p = 0.0; \
else if (p > 1.0) \
p = 1.0; \
} while (0)
Move ltree parentsel() selectivity function into /contrib/ltree.
2006-04-27 00:33:36 +02:00
/* Return data from examine_variable and friends */
Add hooks to let plugins override the planner's lookups in pg_statistic. Simon Riggs, with some editorialization by me.
2008-09-28 21:51:40 +02:00
typedef struct VariableStatData
Move ltree parentsel() selectivity function into /contrib/ltree.
2006-04-27 00:33:36 +02:00
{
Node *var; /* the Var or expression tree */
RelOptInfo *rel; /* Relation, or NULL if not identifiable */
HeapTuple statsTuple; /* pg_statistic tuple, or NULL if none */
/* NB: if statsTuple!=NULL, it must be freed when caller is done */
Add hooks to let plugins override the planner's lookups in pg_statistic. Simon Riggs, with some editorialization by me.
2008-09-28 21:51:40 +02:00
void (*freefunc) (HeapTuple tuple); /* how to free statsTuple */
Move ltree parentsel() selectivity function into /contrib/ltree.
2006-04-27 00:33:36 +02:00
Oid vartype; /* exposed type of expression */
Oid atttype; /* type to pass to get_attstatsslot */
int32 atttypmod; /* typmod to pass to get_attstatsslot */
Improve statistics estimation to make some use of DISTINCT in sub-queries. Formerly, we just punted when trying to estimate stats for variables coming out of sub-queries using DISTINCT, on the grounds that whatever stats we might have for underlying table columns would be inapplicable. But if the sub-query has only one DISTINCT column, we can consider its output variable as being unique, which is useful information all by itself. The scope of this improvement is pretty narrow, but it costs nearly nothing, so we might as well do it. Per discussion with Andres Freund. This patch differs from the draft I submitted yesterday in updating various comments about vardata.isunique (to reflect its extended meaning) and in tweaking the interaction with security_barrier views. There does not seem to be a reason why we can't use this sort of knowledge even when the sub-query is such a view.
2012-02-16 23:33:28 +01:00
bool isunique; /* matches unique index or DISTINCT clause */
Move ltree parentsel() selectivity function into /contrib/ltree.
2006-04-27 00:33:36 +02:00
} VariableStatData;
#define ReleaseVariableStats(vardata) \
do { \
if (HeapTupleIsValid((vardata).statsTuple)) \
Add hooks to let plugins override the planner's lookups in pg_statistic. Simon Riggs, with some editorialization by me.
2008-09-28 21:51:40 +02:00
(* (vardata).freefunc) ((vardata).statsTuple); \
Move ltree parentsel() selectivity function into /contrib/ltree.
2006-04-27 00:33:36 +02:00
} while(0)
Optimizer can now estimate selectivity of IS NULL, IS NOT NULL, IS TRUE, etc, with some degree of verisimilitude. Split out selectivity support functions from builtins.h into a new header file selfuncs.h, so as to reduce the number of header files builtins.h must depend on. Fix a few missing inclusions exposed thereby. From Joe Conway, with some kibitzing from Tom Lane.
2001-06-25 23:11:45 +02:00
typedef enum
{
Another pgindent run. Fixes enum indenting, and improves #endif spacing. Also adds space for one-line comments.
2001-10-28 07:26:15 +01:00
Pattern_Type_Like, Pattern_Type_Like_IC,
Pattern_Type_Regex, Pattern_Type_Regex_IC
Optimizer can now estimate selectivity of IS NULL, IS NOT NULL, IS TRUE, etc, with some degree of verisimilitude. Split out selectivity support functions from builtins.h into a new header file selfuncs.h, so as to reduce the number of header files builtins.h must depend on. Fix a few missing inclusions exposed thereby. From Joe Conway, with some kibitzing from Tom Lane.
2001-06-25 23:11:45 +02:00
} Pattern_Type;
typedef enum
{
Another pgindent run. Fixes enum indenting, and improves #endif spacing. Also adds space for one-line comments.
2001-10-28 07:26:15 +01:00
Pattern_Prefix_None, Pattern_Prefix_Partial, Pattern_Prefix_Exact
Optimizer can now estimate selectivity of IS NULL, IS NOT NULL, IS TRUE, etc, with some degree of verisimilitude. Split out selectivity support functions from builtins.h into a new header file selfuncs.h, so as to reduce the number of header files builtins.h must depend on. Fix a few missing inclusions exposed thereby. From Joe Conway, with some kibitzing from Tom Lane.
2001-06-25 23:11:45 +02:00
} Pattern_Prefix_Status;
Add hooks to let plugins override the planner's lookups in pg_statistic. Simon Riggs, with some editorialization by me.
2008-09-28 21:51:40 +02:00
/* Hooks for plugins to get control when we ask for stats */
typedef bool (*get_relation_stats_hook_type) (PlannerInfo *root,
8.4 pgindent run, with new combined Linux/FreeBSD/MinGW typedef list provided by Andrew.
2009-06-11 16:49:15 +02:00
RangeTblEntry *rte,
AttrNumber attnum,
VariableStatData *vardata);
Add hooks to let plugins override the planner's lookups in pg_statistic. Simon Riggs, with some editorialization by me.
2008-09-28 21:51:40 +02:00
extern PGDLLIMPORT get_relation_stats_hook_type get_relation_stats_hook;
typedef bool (*get_index_stats_hook_type) (PlannerInfo *root,
8.4 pgindent run, with new combined Linux/FreeBSD/MinGW typedef list provided by Andrew.
2009-06-11 16:49:15 +02:00
Oid indexOid,
AttrNumber indexattnum,
VariableStatData *vardata);
Add hooks to let plugins override the planner's lookups in pg_statistic. Simon Riggs, with some editorialization by me.
2008-09-28 21:51:40 +02:00
extern PGDLLIMPORT get_index_stats_hook_type get_index_stats_hook;
Collect and use element-frequency statistics for arrays. This patch improves selectivity estimation for the array <@, &&, and @> (containment and overlaps) operators. It enables collection of statistics about individual array element values by ANALYZE, and introduces operator-specific estimators that use these stats. In addition, ScalarArrayOpExpr constructs of the forms "const = ANY/ALL (array_column)" and "const <> ANY/ALL (array_column)" are estimated by treating them as variants of the containment operators. Since we still collect scalar-style stats about the array values as a whole, the pg_stats view is expanded to show both these stats and the array-style stats in separate columns. This creates an incompatible change in how stats for tsvector columns are displayed in pg_stats: the stats about lexemes are now displayed in the array-related columns instead of the original scalar-related columns. There are a few loose ends here, notably that it'd be nice to be able to suppress either the scalar-style stats or the array-element stats for columns for which they're not useful. But the patch is in good enough shape to commit for wider testing. Alexander Korotkov, reviewed by Noah Misch and Nathan Boley
2012-03-04 02:20:19 +01:00
/* Functions in selfuncs.c */
If we're going to expose VariableStatData for contrib modules to use, then we should export a reasonable set of the supporting routines too.
2006-04-27 02:46:59 +02:00
extern void examine_variable(PlannerInfo *root, Node *node, int varRelid,
pgindent run for 8.2.
2006-10-04 02:30:14 +02:00
VariableStatData *vardata);
If we're going to expose VariableStatData for contrib modules to use, then we should export a reasonable set of the supporting routines too.
2006-04-27 02:46:59 +02:00
extern bool get_restriction_variable(PlannerInfo *root, List *args,
pgindent run for 8.2.
2006-10-04 02:30:14 +02:00
int varRelid,
VariableStatData *vardata, Node **other,
bool *varonleft);
If we're going to expose VariableStatData for contrib modules to use, then we should export a reasonable set of the supporting routines too.
2006-04-27 02:46:59 +02:00
extern void get_join_variables(PlannerInfo *root, List *args,
Clean up the loose ends in selectivity estimation left by my patch for semi and anti joins. To do this, pass the SpecialJoinInfo struct for the current join as an additional optional argument to operator join selectivity estimation functions. This allows the estimator to tell not only what kind of join is being formed, but which variable is on which side of the join; a requirement long recognized but not dealt with till now. This also leaves the door open for future improvements in the estimators, such as accounting for the null-insertion effects of lower outer joins. I didn't do anything about that in the current patch but the information is in principle deducible from what's passed. The patch also clarifies the definition of join selectivity for semi/anti joins: it's the fraction of the left input that has (at least one) match in the right input. This allows getting rid of some very fuzzy thinking that I had committed in the original 7.4-era IN-optimization patch. There's probably room to estimate this better than the present patch does, but at least we know what to estimate. Since I had to touch CREATE OPERATOR anyway to allow a variant signature for join estimator functions, I took the opportunity to add a couple of additional checks that were missing, per my recent message to -hackers: * Check that estimator functions return float8; * Require execute permission at the time of CREATE OPERATOR on the operator's function as well as the estimator functions; * Require ownership of any pre-existing operator that's modified by the command. I also moved the lookup of the functions out of OperatorCreate() and into operatorcmds.c, since that seemed more consistent with most of the other catalog object creation processes, eg CREATE TYPE.
2008-08-16 02:01:38 +02:00
SpecialJoinInfo *sjinfo,
pgindent run for 8.2.
2006-10-04 02:30:14 +02:00
VariableStatData *vardata1,
Clean up the loose ends in selectivity estimation left by my patch for semi and anti joins. To do this, pass the SpecialJoinInfo struct for the current join as an additional optional argument to operator join selectivity estimation functions. This allows the estimator to tell not only what kind of join is being formed, but which variable is on which side of the join; a requirement long recognized but not dealt with till now. This also leaves the door open for future improvements in the estimators, such as accounting for the null-insertion effects of lower outer joins. I didn't do anything about that in the current patch but the information is in principle deducible from what's passed. The patch also clarifies the definition of join selectivity for semi/anti joins: it's the fraction of the left input that has (at least one) match in the right input. This allows getting rid of some very fuzzy thinking that I had committed in the original 7.4-era IN-optimization patch. There's probably room to estimate this better than the present patch does, but at least we know what to estimate. Since I had to touch CREATE OPERATOR anyway to allow a variant signature for join estimator functions, I took the opportunity to add a couple of additional checks that were missing, per my recent message to -hackers: * Check that estimator functions return float8; * Require execute permission at the time of CREATE OPERATOR on the operator's function as well as the estimator functions; * Require ownership of any pre-existing operator that's modified by the command. I also moved the lookup of the functions out of OperatorCreate() and into operatorcmds.c, since that seemed more consistent with most of the other catalog object creation processes, eg CREATE TYPE.
2008-08-16 02:01:38 +02:00
VariableStatData *vardata2,
bool *join_is_reversed);
Change get_variable_numdistinct's API to flag default estimates explicitly. Formerly, callers tested for DEFAULT_NUM_DISTINCT, which had the problem that a perfectly solid estimate might be mistaken for a content-free default.
2011-09-04 21:41:49 +02:00
extern double get_variable_numdistinct(VariableStatData *vardata,
Run pgindent on 9.2 source tree in preparation for first 9.3 commit-fest.
2012-06-10 21:20:04 +02:00
bool *isdefault);
If we're going to expose VariableStatData for contrib modules to use, then we should export a reasonable set of the supporting routines too.
2006-04-27 02:46:59 +02:00
extern double mcv_selectivity(VariableStatData *vardata, FmgrInfo *opproc,
pgindent run for 8.2.
2006-10-04 02:30:14 +02:00
Datum constval, bool varonleft,
double *sumcommonp);
Change patternsel (LIKE/regex selectivity estimation) so that if there is a large enough histogram, it will use the number of matches in the histogram to derive a selectivity estimate, rather than the admittedly pretty bogus heuristics involving examining the pattern contents. I set 'large enough' at 100, but perhaps we should change that later. Also apply the same technique in contrib/ltree's <@ and @> estimator. Per discussion with Stefan Kaltenbrunner and Matteo Beccati.
2006-09-20 21:50:21 +02:00
extern double histogram_selectivity(VariableStatData *vardata, FmgrInfo *opproc,
pgindent run for 8.2.
2006-10-04 02:30:14 +02:00
Datum constval, bool varonleft,
Change patternsel() so that instead of switching from a pure pattern-examination heuristic method to purely histogram-driven selectivity at histogram size 100, we compute both estimates and use a weighted average. The weight put on the heuristic estimate decreases linearly with histogram size, dropping to zero for 100 or more histogram entries. Likewise in ltreeparentsel(). After a patch by Greg Stark, though I reorganized the logic a bit to give the caller of histogram_selectivity() more control.
2008-03-09 01:32:09 +01:00
int min_hist_size, int n_skip,
int *hist_size);
If we're going to expose VariableStatData for contrib modules to use, then we should export a reasonable set of the supporting routines too.
2006-04-27 02:46:59 +02:00
> Okay. When you get back to the original issue, the gold is hidden in > src/backend/optimizer/path/indxpath.c; see the "special indexable > operators" stuff near the bottom of that file. (It's a bit of a crock > that this code is hardwired there, and not somehow accessed through a > system catalog, but it's what we've got at the moment.) The attached patch re-enables a bytea right hand argument (as compared to a text right hand argument), and enables index usage, for bytea LIKE Joe Conway
2002-09-02 08:22:20 +02:00
extern Pattern_Prefix_Status pattern_fixed_prefix(Const *patt,
Optimizer can now estimate selectivity of IS NULL, IS NOT NULL, IS TRUE, etc, with some degree of verisimilitude. Split out selectivity support functions from builtins.h into a new header file selfuncs.h, so as to reduce the number of header files builtins.h must depend on. Fix a few missing inclusions exposed thereby. From Joe Conway, with some kibitzing from Tom Lane.
2001-06-25 23:11:45 +02:00
Pattern_Type ptype,
Teach pattern_fixed_prefix() about collations. This is necessary, not optional, now that ILIKE and regexes are collation aware --- else we might derive a wrong comparison constant for index optimized pattern matches.
2011-04-11 18:28:28 +02:00
Oid collation,
> Okay. When you get back to the original issue, the gold is hidden in > src/backend/optimizer/path/indxpath.c; see the "special indexable > operators" stuff near the bottom of that file. (It's a bit of a crock > that this code is hardwired there, and not somehow accessed through a > system catalog, but it's what we've got at the moment.) The attached patch re-enables a bytea right hand argument (as compared to a text right hand argument), and enables index usage, for bytea LIKE Joe Conway
2002-09-02 08:22:20 +02:00
Const **prefix,
Refactor pattern_fixed_prefix() to avoid dealing in incomplete patterns. Previously, pattern_fixed_prefix() was defined to return whatever fixed prefix it could extract from the pattern, plus the "rest" of the pattern. That definition was sensible for LIKE patterns, but not so much for regexes, where reconstituting a valid pattern minus the prefix could be quite tricky (certainly the existing code wasn't doing that correctly). Since the only thing that callers ever did with the "rest" of the pattern was to pass it to like_selectivity() or regex_selectivity(), let's cut out the middle-man and just have pattern_fixed_prefix's subroutines do this directly. Then pattern_fixed_prefix can return a simple selectivity number, and the question of how to cope with partial patterns is removed from its API specification. While at it, adjust the API spec so that callers who don't actually care about the pattern's selectivity (which is a lot of them) can pass NULL for the selectivity pointer to skip doing the work of computing a selectivity estimate. This patch is only an API refactoring that doesn't actually change any processing, other than allowing a little bit of useless work to be skipped. However, it's necessary infrastructure for my upcoming fix to regex prefix extraction, because after that change there won't be any simple way to identify the "rest" of the regex, not even to the low level of fidelity needed by regex_selectivity. We can cope with that if regex_fixed_prefix and regex_selectivity communicate directly, but not if we have to work within the old API. Hence, back-patch to all active branches.
2012-07-10 05:22:55 +02:00
Selectivity *rest_selec);
Pass collations to functions in FunctionCallInfoData, not FmgrInfo. Since collation is effectively an argument, not a property of the function, FmgrInfo is really the wrong place for it; and this becomes critical in cases where a cached FmgrInfo is used for varying purposes that might need different collation settings. Fix by passing it in FunctionCallInfoData instead. In particular this allows a clean fix for bug #5970 (record_cmp not working). This requires touching a bit more code than the original method, but nobody ever thought that collations would not be an invasive patch...
2011-04-13 01:19:24 +02:00
extern Const *make_greater_string(const Const *str_const, FmgrInfo *ltproc,
Pgindent run before 9.1 beta2.
2011-06-09 20:32:50 +02:00
Oid collation);
Optimizer can now estimate selectivity of IS NULL, IS NOT NULL, IS TRUE, etc, with some degree of verisimilitude. Split out selectivity support functions from builtins.h into a new header file selfuncs.h, so as to reduce the number of header files builtins.h must depend on. Fix a few missing inclusions exposed thereby. From Joe Conway, with some kibitzing from Tom Lane.
2001-06-25 23:11:45 +02:00
extern Datum eqsel(PG_FUNCTION_ARGS);
extern Datum neqsel(PG_FUNCTION_ARGS);
extern Datum scalarltsel(PG_FUNCTION_ARGS);
extern Datum scalargtsel(PG_FUNCTION_ARGS);
extern Datum regexeqsel(PG_FUNCTION_ARGS);
extern Datum icregexeqsel(PG_FUNCTION_ARGS);
extern Datum likesel(PG_FUNCTION_ARGS);
extern Datum iclikesel(PG_FUNCTION_ARGS);
extern Datum regexnesel(PG_FUNCTION_ARGS);
extern Datum icregexnesel(PG_FUNCTION_ARGS);
extern Datum nlikesel(PG_FUNCTION_ARGS);
extern Datum icnlikesel(PG_FUNCTION_ARGS);
extern Datum eqjoinsel(PG_FUNCTION_ARGS);
extern Datum neqjoinsel(PG_FUNCTION_ARGS);
extern Datum scalarltjoinsel(PG_FUNCTION_ARGS);
extern Datum scalargtjoinsel(PG_FUNCTION_ARGS);
extern Datum regexeqjoinsel(PG_FUNCTION_ARGS);
extern Datum icregexeqjoinsel(PG_FUNCTION_ARGS);
extern Datum likejoinsel(PG_FUNCTION_ARGS);
extern Datum iclikejoinsel(PG_FUNCTION_ARGS);
extern Datum regexnejoinsel(PG_FUNCTION_ARGS);
extern Datum icregexnejoinsel(PG_FUNCTION_ARGS);
extern Datum nlikejoinsel(PG_FUNCTION_ARGS);
extern Datum icnlikejoinsel(PG_FUNCTION_ARGS);
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.
2005-06-06 00:32:58 +02:00
extern Selectivity booltestsel(PlannerInfo *root, BoolTestType booltesttype,
Implement SEMI and ANTI joins in the planner and executor. (Semijoins replace the old JOIN_IN code, but antijoins are new functionality.) Teach the planner to convert appropriate EXISTS and NOT EXISTS subqueries into semi and anti joins respectively. Also, LEFT JOINs with suitable upper-level IS NULL filters are recognized as being anti joins. Unify the InClauseInfo and OuterJoinInfo infrastructure into "SpecialJoinInfo". With that change, it becomes possible to associate a SpecialJoinInfo with every join attempt, which permits some cleanup of join selectivity estimation. That needs to be taken much further than this patch does, but the next step is to change the API for oprjoin selectivity functions, which seems like material for a separate patch. So for the moment the output size estimates for semi and especially anti joins are quite bogus.
2008-08-14 20:48:00 +02:00
Node *arg, int varRelid,
JoinType jointype, SpecialJoinInfo *sjinfo);
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.
2005-06-06 00:32:58 +02:00
extern Selectivity nulltestsel(PlannerInfo *root, NullTestType nulltesttype,
Implement SEMI and ANTI joins in the planner and executor. (Semijoins replace the old JOIN_IN code, but antijoins are new functionality.) Teach the planner to convert appropriate EXISTS and NOT EXISTS subqueries into semi and anti joins respectively. Also, LEFT JOINs with suitable upper-level IS NULL filters are recognized as being anti joins. Unify the InClauseInfo and OuterJoinInfo infrastructure into "SpecialJoinInfo". With that change, it becomes possible to associate a SpecialJoinInfo with every join attempt, which permits some cleanup of join selectivity estimation. That needs to be taken much further than this patch does, but the next step is to change the API for oprjoin selectivity functions, which seems like material for a separate patch. So for the moment the output size estimates for semi and especially anti joins are quite bogus.
2008-08-14 20:48:00 +02:00
Node *arg, int varRelid,
JoinType jointype, SpecialJoinInfo *sjinfo);
Teach planner and executor to handle ScalarArrayOpExpr as an indexable qualification when the underlying operator is indexable and useOr is true. That is, indexkey op ANY (ARRAY[...]) is effectively translated into an OR combination of one indexscan for each array element. This only works for bitmap index scans, of course, since regular indexscans no longer support OR'ing of scans. There are still some loose ends to clean up before changing 'x IN (list)' to translate as a ScalarArrayOpExpr; for instance predtest.c ought to be taught about it. But this gets the basic functionality in place.
2005-11-25 20:47:50 +01:00
extern Selectivity scalararraysel(PlannerInfo *root,
pgindent run for 8.2.
2006-10-04 02:30:14 +02:00
ScalarArrayOpExpr *clause,
bool is_join_clause,
Implement SEMI and ANTI joins in the planner and executor. (Semijoins replace the old JOIN_IN code, but antijoins are new functionality.) Teach the planner to convert appropriate EXISTS and NOT EXISTS subqueries into semi and anti joins respectively. Also, LEFT JOINs with suitable upper-level IS NULL filters are recognized as being anti joins. Unify the InClauseInfo and OuterJoinInfo infrastructure into "SpecialJoinInfo". With that change, it becomes possible to associate a SpecialJoinInfo with every join attempt, which permits some cleanup of join selectivity estimation. That needs to be taken much further than this patch does, but the next step is to change the API for oprjoin selectivity functions, which seems like material for a separate patch. So for the moment the output size estimates for semi and especially anti joins are quite bogus.
2008-08-14 20:48:00 +02:00
int varRelid, JoinType jointype, SpecialJoinInfo *sjinfo);
Fix oversight in planning for multiple indexscans driven by ScalarArrayOpExpr index quals: we were estimating the right total number of rows returned, but treating the index-access part of the cost as if a single scan were fetching that many consecutive index tuples. Actually we should treat it as a multiple indexscan, and if there are enough of 'em the Mackert-Lohman discount should kick in.
2006-07-02 00:07:23 +02:00
extern int estimate_array_length(Node *arrayexpr);
Add selectivity-calculation code for RowCompareExpr nodes. Simplistic, but a lot better than nothing at all ...
2006-01-14 01:14:12 +01:00
extern Selectivity rowcomparesel(PlannerInfo *root,
pgindent run for 8.2.
2006-10-04 02:30:14 +02:00
RowCompareExpr *clause,
Implement SEMI and ANTI joins in the planner and executor. (Semijoins replace the old JOIN_IN code, but antijoins are new functionality.) Teach the planner to convert appropriate EXISTS and NOT EXISTS subqueries into semi and anti joins respectively. Also, LEFT JOINs with suitable upper-level IS NULL filters are recognized as being anti joins. Unify the InClauseInfo and OuterJoinInfo infrastructure into "SpecialJoinInfo". With that change, it becomes possible to associate a SpecialJoinInfo with every join attempt, which permits some cleanup of join selectivity estimation. That needs to be taken much further than this patch does, but the next step is to change the API for oprjoin selectivity functions, which seems like material for a separate patch. So for the moment the output size estimates for semi and especially anti joins are quite bogus.
2008-08-14 20:48:00 +02:00
int varRelid, JoinType jointype, SpecialJoinInfo *sjinfo);
Teach planner about the idea that a mergejoin won't necessarily read both input streams to the end. If one variable's range is much less than the other, an indexscan-based merge can win by not scanning all of the other table. Per example from Reinhard Max.
2002-03-01 05:09:28 +01:00
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.
2005-06-06 00:32:58 +02:00
extern void mergejoinscansel(PlannerInfo *root, Node *clause,
Make all comparisons done for/with statistics use the default collation. While this will give wrong answers when estimating selectivity for a comparison operator that's using a non-default collation, the estimation error probably won't be large; and anyway the former approach created estimation errors of its own by trying to use a histogram that might have been computed with some other collation. So we'll adopt this simplified approach for now and perhaps improve it sometime in the future. This patch incorporates changes from Andres Freund to make sure that selfuncs.c passes a valid collation OID to any datatype-specific function it calls, in case that function wants collation information. Said OID will now always be DEFAULT_COLLATION_OID, but at least we won't get errors.
2011-03-12 22:30:36 +01:00
Oid opfamily, int strategy, bool nulls_first,
Fix mergejoin cost estimation so that we consider the statistical ranges of the two join variables at both ends: not only trailing rows that need not be scanned because there cannot be a match on the other side, but initial rows that will be scanned without possibly having a match. This allows a more realistic estimate of startup cost to be made, per recent pgsql-performance discussion. In passing, fix a couple of bugs that had crept into mergejoinscansel: it was not quite up to speed for the task of estimating descending-order scans, which is a new requirement in 8.3.
2007-12-08 22:05:11 +01:00
Selectivity *leftstart, Selectivity *leftend,
Selectivity *rightstart, Selectivity *rightend);
Optimizer can now estimate selectivity of IS NULL, IS NOT NULL, IS TRUE, etc, with some degree of verisimilitude. Split out selectivity support functions from builtins.h into a new header file selfuncs.h, so as to reduce the number of header files builtins.h must depend on. Fix a few missing inclusions exposed thereby. From Joe Conway, with some kibitzing from Tom Lane.
2001-06-25 23:11:45 +02:00
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.
2005-06-06 00:32:58 +02:00
extern double estimate_num_groups(PlannerInfo *root, List *groupExprs,
pgindent run for 9.5
2015-05-24 03:35:49 +02:00
double input_rows, List **pgset);
Add an at-least-marginally-plausible method of estimating the number of groups produced by GROUP BY. This improves the accuracy of planning estimates for grouped subselects, and is needed to check whether a hashed aggregation plan risks memory overflow.
2002-11-20 00:22:00 +01:00
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.
2005-06-06 00:32:58 +02:00
extern Selectivity estimate_hash_bucketsize(PlannerInfo *root, Node *hashkey,
Revise hash join code so that we can increase the number of batches on-the-fly, and thereby avoid blowing out memory when the planner has underestimated the hash table size. Hash join will now obey the work_mem limit with some faithfulness. Per my recent proposal (hash aggregate part isn't done yet though).
2005-03-06 23:15:05 +01:00
double nbuckets);
Make use of statistics on index expressions. There are still some corner cases that could stand improvement, but it does all the basic stuff. A byproduct is that the selectivity routines are no longer constrained to working on simple Vars; we might in future be able to improve the behavior for subexpressions that don't match indexes.
2004-02-17 01:52:53 +01:00
BRIN: Block Range Indexes BRIN is a new index access method intended to accelerate scans of very large tables, without the maintenance overhead of btrees or other traditional indexes. They work by maintaining "summary" data about block ranges. Bitmap index scans work by reading each summary tuple and comparing them with the query quals; all pages in the range are returned in a lossy TID bitmap if the quals are consistent with the values in the summary tuple, otherwise not. Normal index scans are not supported because these indexes do not store TIDs. As new tuples are added into the index, the summary information is updated (if the block range in which the tuple is added is already summarized) or not; in the latter case, a subsequent pass of VACUUM or the brin_summarize_new_values() function will create the summary information. For data types with natural 1-D sort orders, the summary info consists of the maximum and the minimum values of each indexed column within each page range. This type of operator class we call "Minmax", and we supply a bunch of them for most data types with B-tree opclasses. Since the BRIN code is generalized, other approaches are possible for things such as arrays, geometric types, ranges, etc; even for things such as enum types we could do something different than minmax with better results. In this commit I only include minmax. Catalog version bumped due to new builtin catalog entries. There's more that could be done here, but this is a good step forwards. Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera, with contribution by Heikki Linnakangas. Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas. Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo. PS: The research leading to these results has received funding from the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
extern Datum brincostestimate(PG_FUNCTION_ARGS);
Optimizer can now estimate selectivity of IS NULL, IS NOT NULL, IS TRUE, etc, with some degree of verisimilitude. Split out selectivity support functions from builtins.h into a new header file selfuncs.h, so as to reduce the number of header files builtins.h must depend on. Fix a few missing inclusions exposed thereby. From Joe Conway, with some kibitzing from Tom Lane.
2001-06-25 23:11:45 +02:00
extern Datum btcostestimate(PG_FUNCTION_ARGS);
extern Datum hashcostestimate(PG_FUNCTION_ARGS);
extern Datum gistcostestimate(PG_FUNCTION_ARGS);
Add SP-GiST (space-partitioned GiST) index access method. SP-GiST is comparable to GiST in flexibility, but supports non-balanced partitioned search structures rather than balanced trees. As described at PGCon 2011, this new indexing structure can beat GiST in both index build time and query speed for search problems that it is well matched to. There are a number of areas that could still use improvement, but at this point the code seems committable. Teodor Sigaev and Oleg Bartunov, with considerable revisions by Tom Lane
2011-12-17 22:41:16 +01:00
extern Datum spgcostestimate(PG_FUNCTION_ARGS);
GIN: Generalized Inverted iNdex. text[], int4[], Tsearch2 support for GIN.
2006-05-02 13:28:56 +02:00
extern Datum gincostestimate(PG_FUNCTION_ARGS);
Enhanced containment selectivity function for /contrib/ltree Matteo Beccati
2006-04-26 20:28:34 +02:00
Collect and use element-frequency statistics for arrays. This patch improves selectivity estimation for the array <@, &&, and @> (containment and overlaps) operators. It enables collection of statistics about individual array element values by ANALYZE, and introduces operator-specific estimators that use these stats. In addition, ScalarArrayOpExpr constructs of the forms "const = ANY/ALL (array_column)" and "const <> ANY/ALL (array_column)" are estimated by treating them as variants of the containment operators. Since we still collect scalar-style stats about the array values as a whole, the pg_stats view is expanded to show both these stats and the array-style stats in separate columns. This creates an incompatible change in how stats for tsvector columns are displayed in pg_stats: the stats about lexemes are now displayed in the array-related columns instead of the original scalar-related columns. There are a few loose ends here, notably that it'd be nice to be able to suppress either the scalar-style stats or the array-element stats for columns for which they're not useful. But the patch is in good enough shape to commit for wider testing. Alexander Korotkov, reviewed by Noah Misch and Nathan Boley
2012-03-04 02:20:19 +01:00
/* Functions in array_selfuncs.c */
extern Selectivity scalararraysel_containment(PlannerInfo *root,
Node *leftop, Node *rightop,
Oid elemtype, bool isEquality, bool useOr,
int varRelid);
extern Datum arraycontsel(PG_FUNCTION_ARGS);
extern Datum arraycontjoinsel(PG_FUNCTION_ARGS);
New pgindent run with fixes suggested by Tom. Patch manually reviewed, initdb/regression tests pass.
2001-11-05 18:46:40 +01:00
#endif /* SELFUNCS_H */