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Postgres FD Implementation
Commit 82849df6 authored by Tom Lane's avatar Tom Lane
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Add new selectivity estimation functions for pattern-matching operators 

(LIKE and regexp matches).  These are not yet referenced in pg_operator,
so by default the system will continue to use eqsel/neqsel.
Also, tweak convert_to_scalar() logic so that common prefixes of strings
are stripped off, allowing better accuracy when all strings in a table
share a common prefix.
parent 8c3b52e7
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Showing with 1339 additions and 469 deletions
doc/src/sgml/xoper.sgml
View file @ 82849df6
<!--
$Header: /cvsroot/pgsql/doc/src/sgml/xoper.sgml,v 1.9 2000/03/31 03:27:41 thomas Exp $
$Header: /cvsroot/pgsql/doc/src/sgml/xoper.sgml,v 1.10 2000/04/16 04:41:01 tgl Exp $
-->
<Chapter Id="xoper">
......@@ -254,9 +254,9 @@ SELECT (a + b) AS c FROM test_complex;
<para>
You can frequently get away with using either eqsel or neqsel for
operators that have very high or very low selectivity, even if they
aren't really equality or inequality. For example, the regular expression
matching operators (~, ~*, etc) use eqsel on the assumption that they'll
usually only match a small fraction of the entries in a table.
aren't really equality or inequality. For example, the
approximate-equality geometric operators use eqsel on the assumption that
they'll usually only match a small fraction of the entries in a table.
</para>
<para>
......
src/backend/optimizer/path/indxpath.c
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src/backend/utils/adt/selfuncs.c
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src/include/catalog/pg_proc.h
View file @ 82849df6
......@@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2000, PostgreSQL, Inc
* Portions Copyright (c) 1994, Regents of the University of California
*
* $Id: pg_proc.h,v 1.132 2000/04/12 17:16:29 momjian Exp $
* $Id: pg_proc.h,v 1.133 2000/04/16 04:41:03 tgl Exp $
*
* NOTES
* The script catalog/genbki.sh reads this file and generates .bki
......@@ -2436,6 +2436,32 @@ DESCR("convert text to timestamp");
DATA(insert OID = 1780 ( to_date PGUID 11 f t f 2 f 1082 "25 25" 100 0 0 100 to_date - ));
DESCR("convert text to date");
/* Selectivity estimators for LIKE and related operators */
DATA(insert OID = 1818 ( regexeqsel PGUID 11 f t f 5 f 701 "26 26 21 0 23" 100 0 0 100 regexeqsel - ));
DESCR("restriction selectivity of regex match");
DATA(insert OID = 1819 ( likesel PGUID 11 f t f 5 f 701 "26 26 21 0 23" 100 0 0 100 likesel - ));
DESCR("restriction selectivity of LIKE");
DATA(insert OID = 1820 ( icregexeqsel PGUID 11 f t f 5 f 701 "26 26 21 0 23" 100 0 0 100 icregexeqsel - ));
DESCR("restriction selectivity of case-insensitive regex match");
DATA(insert OID = 1821 ( regexnesel PGUID 11 f t f 5 f 701 "26 26 21 0 23" 100 0 0 100 regexnesel - ));
DESCR("restriction selectivity of regex non-match");
DATA(insert OID = 1822 ( nlikesel PGUID 11 f t f 5 f 701 "26 26 21 0 23" 100 0 0 100 nlikesel - ));
DESCR("restriction selectivity of NOT LIKE");
DATA(insert OID = 1823 ( icregexnesel PGUID 11 f t f 5 f 701 "26 26 21 0 23" 100 0 0 100 icregexnesel - ));
DESCR("restriction selectivity of case-insensitive regex non-match");
DATA(insert OID = 1824 ( regexeqjoinsel PGUID 11 f t f 5 f 701 "26 26 21 26 21" 100 0 0 100 regexeqjoinsel - ));
DESCR("join selectivity of regex match");
DATA(insert OID = 1825 ( likejoinsel PGUID 11 f t f 5 f 701 "26 26 21 26 21" 100 0 0 100 likejoinsel - ));
DESCR("join selectivity of LIKE");
DATA(insert OID = 1826 ( icregexeqjoinsel PGUID 11 f t f 5 f 701 "26 26 21 26 21" 100 0 0 100 icregexeqjoinsel - ));
DESCR("join selectivity of case-insensitive regex match");
DATA(insert OID = 1827 ( regexnejoinsel PGUID 11 f t f 5 f 701 "26 26 21 26 21" 100 0 0 100 regexnejoinsel - ));
DESCR("join selectivity of regex non-match");
DATA(insert OID = 1828 ( nlikejoinsel PGUID 11 f t f 5 f 701 "26 26 21 26 21" 100 0 0 100 nlikejoinsel - ));
DESCR("join selectivity of NOT LIKE");
DATA(insert OID = 1829 ( icregexnejoinsel PGUID 11 f t f 5 f 701 "26 26 21 26 21" 100 0 0 100 icregexnejoinsel - ));
DESCR("join selectivity of case-insensitive regex non-match");
/*
* prototypes for functions pg_proc.c
......
src/include/utils/builtins.h
View file @ 82849df6
......@@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2000, PostgreSQL, Inc
* Portions Copyright (c) 1994, Regents of the University of California
*
* $Id: builtins.h,v 1.110 2000/04/12 17:16:54 momjian Exp $
* $Id: builtins.h,v 1.111 2000/04/16 04:41:03 tgl Exp $
*
* NOTES
* This should normally only be included by fmgr.h.
......@@ -371,15 +371,47 @@ extern char *deparse_expression(Node *expr, List *rangetables,
bool forceprefix);
/* selfuncs.c */
extern float64 eqsel(Oid opid, Oid relid, AttrNumber attno, Datum value, int32 flag);
extern float64 neqsel(Oid opid, Oid relid, AttrNumber attno, Datum value, int32 flag);
extern float64 scalarltsel(Oid opid, Oid relid, AttrNumber attno, Datum value, int32 flag);
extern float64 scalargtsel(Oid opid, Oid relid, AttrNumber attno, Datum value, int32 flag);
extern float64 eqjoinsel(Oid opid, Oid relid1, AttrNumber attno1, Oid relid2, AttrNumber attno2);
extern float64 neqjoinsel(Oid opid, Oid relid1, AttrNumber attno1, Oid relid2, AttrNumber attno2);
extern float64 scalarltjoinsel(Oid opid, Oid relid1, AttrNumber attno1, Oid relid2, AttrNumber attno2);
extern float64 scalargtjoinsel(Oid opid, Oid relid1, AttrNumber attno1, Oid relid2, AttrNumber attno2);
extern bool convert_to_scalar(Datum value, Oid typid, double *scaleval);
extern float64 eqsel(Oid opid, Oid relid, AttrNumber attno,
Datum value, int32 flag);
extern float64 neqsel(Oid opid, Oid relid, AttrNumber attno,
Datum value, int32 flag);
extern float64 scalarltsel(Oid opid, Oid relid, AttrNumber attno,
Datum value, int32 flag);
extern float64 scalargtsel(Oid opid, Oid relid, AttrNumber attno,
Datum value, int32 flag);
extern float64 regexeqsel(Oid opid, Oid relid, AttrNumber attno,
Datum value, int32 flag);
extern float64 likesel(Oid opid, Oid relid, AttrNumber attno,
Datum value, int32 flag);
extern float64 icregexeqsel(Oid opid, Oid relid, AttrNumber attno,
Datum value, int32 flag);
extern float64 regexnesel(Oid opid, Oid relid, AttrNumber attno,
Datum value, int32 flag);
extern float64 nlikesel(Oid opid, Oid relid, AttrNumber attno,
Datum value, int32 flag);
extern float64 icregexnesel(Oid opid, Oid relid, AttrNumber attno,
Datum value, int32 flag);
extern float64 eqjoinsel(Oid opid, Oid relid1, AttrNumber attno1,
Oid relid2, AttrNumber attno2);
extern float64 neqjoinsel(Oid opid, Oid relid1, AttrNumber attno1,
Oid relid2, AttrNumber attno2);
extern float64 scalarltjoinsel(Oid opid, Oid relid1, AttrNumber attno1,
Oid relid2, AttrNumber attno2);
extern float64 scalargtjoinsel(Oid opid, Oid relid1, AttrNumber attno1,
Oid relid2, AttrNumber attno2);
extern float64 regexeqjoinsel(Oid opid, Oid relid1, AttrNumber attno1,
Oid relid2, AttrNumber attno2);
extern float64 likejoinsel(Oid opid, Oid relid1, AttrNumber attno1,
Oid relid2, AttrNumber attno2);
extern float64 icregexeqjoinsel(Oid opid, Oid relid1, AttrNumber attno1,
Oid relid2, AttrNumber attno2);
extern float64 regexnejoinsel(Oid opid, Oid relid1, AttrNumber attno1,
Oid relid2, AttrNumber attno2);
extern float64 nlikejoinsel(Oid opid, Oid relid1, AttrNumber attno1,
Oid relid2, AttrNumber attno2);
extern float64 icregexnejoinsel(Oid opid, Oid relid1, AttrNumber attno1,
Oid relid2, AttrNumber attno2);
extern void btcostestimate(Query *root, RelOptInfo *rel,
IndexOptInfo *index, List *indexQuals,
......@@ -402,6 +434,22 @@ extern void gistcostestimate(Query *root, RelOptInfo *rel,
Cost *indexTotalCost,
Selectivity *indexSelectivity);
typedef enum
{
Pattern_Type_Like, Pattern_Type_Regex, Pattern_Type_Regex_IC
} Pattern_Type;
typedef enum
{
Pattern_Prefix_None, Pattern_Prefix_Partial, Pattern_Prefix_Exact
} Pattern_Prefix_Status;
extern Pattern_Prefix_Status pattern_fixed_prefix(char *patt,
Pattern_Type ptype,
char **prefix,
char **rest);
extern char *make_greater_string(const char *str, Oid datatype);
/* tid.c */
extern ItemPointer tidin(const char *str);
extern char *tidout(ItemPointer itemPtr);
......
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