database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-09-06 13:46:51 +03:00
Code Activity

Add prefix operator for TEXT type.

Browse Source 
The prefix operator along with SP-GiST indexes can be used as an alternative
for LIKE 'word%' commands  and it doesn't have a limitation of string/prefix
length as B-Tree has.

Bump catalog version

Author: Ildus Kurbangaliev with some editorization by me
Review by: Arthur Zakirov, Alexander Korotkov, and me
Discussion: https://www.postgresql.org/message-id/flat/20180202180327.222b04b3@wp.localdomain
This commit is contained in:
Teodor Sigaev
2018-04-03 19:46:45 +03:00
parent 4ab2999815
commit 710d90da1f
14 changed files with 189 additions and 9 deletions
Download Patch File Download Diff File Expand all files Collapse all files

33
src/backend/utils/adt/selfuncs.c
View File

@@ -1488,6 +1488,16 @@ likesel(PG_FUNCTION_ARGS)
}
/*
* prefixsel - selectivity of prefix operator
*/
Datum
prefixsel(PG_FUNCTION_ARGS)
{
PG_RETURN_FLOAT8(patternsel(fcinfo, Pattern_Type_Prefix, false));
}
/*
*
* iclikesel - Selectivity of ILIKE pattern match.
*/
Datum
@@ -2906,6 +2916,15 @@ likejoinsel(PG_FUNCTION_ARGS)
PG_RETURN_FLOAT8(patternjoinsel(fcinfo, Pattern_Type_Like, false));
}
/*
* prefixjoinsel - Join selectivity of prefix operator
*/
Datum
prefixjoinsel(PG_FUNCTION_ARGS)
{
PG_RETURN_FLOAT8(patternjoinsel(fcinfo, Pattern_Type_Prefix, false));
}
/*
* iclikejoinsel - Join selectivity of ILIKE pattern match.
*/
@@ -5947,6 +5966,20 @@ pattern_fixed_prefix(Const *patt, Pattern_Type ptype, Oid collation,
result = regex_fixed_prefix(patt, true, collation,
prefix, rest_selec);
break;
case Pattern_Type_Prefix:
/* Prefix type work is trivial. */
result = Pattern_Prefix_Partial;
*rest_selec = 1.0; /* all */
*prefix = makeConst(patt->consttype,
patt->consttypmod,
patt->constcollid,
patt->constlen,
datumCopy(patt->constvalue,
patt->constbyval,
patt->constlen),
patt->constisnull,
patt->constbyval);
break;
default:
elog(ERROR, "unrecognized ptype: %d", (int) ptype);
result = Pattern_Prefix_None; /* keep compiler quiet */