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Reimplement LIKE/ESCAPE as operators so that indexscan optimization

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can still work, per recent discussion on pghackers.  Correct some bugs
in ILIKE implementation.
This commit is contained in:
Tom Lane
2000-09-15 18:45:31 +00:00
parent 148f905f41
commit 8ae9ad1cb8
9 changed files with 511 additions and 514 deletions
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68
src/backend/utils/adt/selfuncs.c
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@ -15,7 +15,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/utils/adt/selfuncs.c,v 1.78 2000/08/03 16:34:22 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/utils/adt/selfuncs.c,v 1.79 2000/09/15 18:45:26 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -570,6 +570,15 @@ likesel(PG_FUNCTION_ARGS)
return patternsel(fcinfo, Pattern_Type_Like);
}
/*
* iclikesel - Selectivity of ILIKE pattern match.
*/
Datum
iclikesel(PG_FUNCTION_ARGS)
{
return patternsel(fcinfo, Pattern_Type_Like_IC);
}
/*
* regexnesel - Selectivity of regular-expression pattern non-match.
*/
@ -609,6 +618,19 @@ nlikesel(PG_FUNCTION_ARGS)
PG_RETURN_FLOAT8(result);
}
/*
* icnlikesel - Selectivity of ILIKE pattern non-match.
*/
Datum
icnlikesel(PG_FUNCTION_ARGS)
{
float8 result;
result = DatumGetFloat8(patternsel(fcinfo, Pattern_Type_Like_IC));
result = 1.0 - result;
PG_RETURN_FLOAT8(result);
}
/*
* eqjoinsel - Join selectivity of "="
*/
@ -723,6 +745,15 @@ likejoinsel(PG_FUNCTION_ARGS)
PG_RETURN_FLOAT8(DEFAULT_MATCH_SEL);
}
/*
* iclikejoinsel - Join selectivity of ILIKE pattern match.
*/
Datum
iclikejoinsel(PG_FUNCTION_ARGS)
{
PG_RETURN_FLOAT8(DEFAULT_MATCH_SEL);
}
/*
* regexnejoinsel - Join selectivity of regex non-match.
*/
@ -762,6 +793,19 @@ nlikejoinsel(PG_FUNCTION_ARGS)
PG_RETURN_FLOAT8(result);
}
/*
* icnlikejoinsel - Join selectivity of ILIKE pattern non-match.
*/
Datum
icnlikejoinsel(PG_FUNCTION_ARGS)
{
float8 result;
result = DatumGetFloat8(iclikejoinsel(fcinfo));
result = 1.0 - result;
PG_RETURN_FLOAT8(result);
}
/*
* convert_to_scalar
@ -1337,7 +1381,8 @@ getattstatistics(Oid relid,
*/
static Pattern_Prefix_Status
like_fixed_prefix(char *patt, char **prefix, char **rest)
like_fixed_prefix(char *patt, bool case_insensitive,
char **prefix, char **rest)
{
char *match;
int pos,
@ -1359,7 +1404,12 @@ like_fixed_prefix(char *patt, char **prefix, char **rest)
if (patt[pos] == '\0')
break;
}
/*
* XXX I suspect isalpha() is not an adequately locale-sensitive
* test for characters that can vary under case folding?
*/
if (case_insensitive && isalpha((int) patt[pos]))
break;
/*
* NOTE: this code used to think that %% meant a literal %, but
* textlike() itself does not think that, and the SQL92 spec
@ -1497,7 +1547,10 @@ pattern_fixed_prefix(char *patt, Pattern_Type ptype,
switch (ptype)
{
case Pattern_Type_Like:
result = like_fixed_prefix(patt, prefix, rest);
result = like_fixed_prefix(patt, false, prefix, rest);
break;
case Pattern_Type_Like_IC:
result = like_fixed_prefix(patt, true, prefix, rest);
break;
case Pattern_Type_Regex:
result = regex_fixed_prefix(patt, false, prefix, rest);
@ -1625,7 +1678,7 @@ prefix_selectivity(char *prefix,
#define PARTIAL_WILDCARD_SEL 2.0
static Selectivity
like_selectivity(char *patt)
like_selectivity(char *patt, bool case_insensitive)
{
Selectivity sel = 1.0;
int pos;
@ -1780,7 +1833,10 @@ pattern_selectivity(char *patt, Pattern_Type ptype)
switch (ptype)
{
case Pattern_Type_Like:
result = like_selectivity(patt);
result = like_selectivity(patt, false);
break;
case Pattern_Type_Like_IC:
result = like_selectivity(patt, true);
break;
case Pattern_Type_Regex:
result = regex_selectivity(patt, false);