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Indexing support for pattern matching operations via separate operator

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class when lc_collate is not C.
This commit is contained in:
Peter Eisentraut
2003-05-15 15:50:21 +00:00
parent 2a2f6cfa39
commit 2c0556068f
20 changed files with 489 additions and 208 deletions
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145
src/backend/utils/adt/varlena.c
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@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/utils/adt/varlena.c,v 1.97 2003/05/09 15:44:40 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/utils/adt/varlena.c,v 1.98 2003/05/15 15:50:19 petere Exp $
*
*-------------------------------------------------------------------------
*/
@ -1050,6 +1050,149 @@ text_smaller(PG_FUNCTION_ARGS)
PG_RETURN_TEXT_P(result);
}
/*
* The following operators support character-by-character comparison
* of text data types, to allow building indexes suitable for LIKE
* clauses.
*/
static int
internal_text_pattern_compare(text *arg1, text *arg2)
{
int result;
result = memcmp(VARDATA(arg1), VARDATA(arg2),
Min(VARSIZE(arg1), VARSIZE(arg2)) - VARHDRSZ);
if (result != 0)
return result;
else if (VARSIZE(arg1) < VARSIZE(arg2))
return -1;
else if (VARSIZE(arg1) > VARSIZE(arg2))
return 1;
else
return 0;
}
Datum
text_pattern_lt(PG_FUNCTION_ARGS)
{
text *arg1 = PG_GETARG_TEXT_P(0);
text *arg2 = PG_GETARG_TEXT_P(1);
int result;
result = internal_text_pattern_compare(arg1, arg2);
PG_FREE_IF_COPY(arg1, 0);
PG_FREE_IF_COPY(arg2, 1);
PG_RETURN_BOOL(result < 0);
}
Datum
text_pattern_le(PG_FUNCTION_ARGS)
{
text *arg1 = PG_GETARG_TEXT_P(0);
text *arg2 = PG_GETARG_TEXT_P(1);
int result;
result = internal_text_pattern_compare(arg1, arg2);
PG_FREE_IF_COPY(arg1, 0);
PG_FREE_IF_COPY(arg2, 1);
PG_RETURN_BOOL(result <= 0);
}
Datum
text_pattern_eq(PG_FUNCTION_ARGS)
{
text *arg1 = PG_GETARG_TEXT_P(0);
text *arg2 = PG_GETARG_TEXT_P(1);
int result;
if (VARSIZE(arg1) != VARSIZE(arg2))
result = 1;
else
result = internal_text_pattern_compare(arg1, arg2);
PG_FREE_IF_COPY(arg1, 0);
PG_FREE_IF_COPY(arg2, 1);
PG_RETURN_BOOL(result == 0);
}
Datum
text_pattern_ge(PG_FUNCTION_ARGS)
{
text *arg1 = PG_GETARG_TEXT_P(0);
text *arg2 = PG_GETARG_TEXT_P(1);
int result;
result = internal_text_pattern_compare(arg1, arg2);
PG_FREE_IF_COPY(arg1, 0);
PG_FREE_IF_COPY(arg2, 1);
PG_RETURN_BOOL(result >= 0);
}
Datum
text_pattern_gt(PG_FUNCTION_ARGS)
{
text *arg1 = PG_GETARG_TEXT_P(0);
text *arg2 = PG_GETARG_TEXT_P(1);
int result;
result = internal_text_pattern_compare(arg1, arg2);
PG_FREE_IF_COPY(arg1, 0);
PG_FREE_IF_COPY(arg2, 1);
PG_RETURN_BOOL(result > 0);
}
Datum
text_pattern_ne(PG_FUNCTION_ARGS)
{
text *arg1 = PG_GETARG_TEXT_P(0);
text *arg2 = PG_GETARG_TEXT_P(1);
int result;
if (VARSIZE(arg1) != VARSIZE(arg2))
result = 1;
else
result = internal_text_pattern_compare(arg1, arg2);
PG_FREE_IF_COPY(arg1, 0);
PG_FREE_IF_COPY(arg2, 1);
PG_RETURN_BOOL(result != 0);
}
Datum
bttext_pattern_cmp(PG_FUNCTION_ARGS)
{
text *arg1 = PG_GETARG_TEXT_P(0);
text *arg2 = PG_GETARG_TEXT_P(1);
int result;
result = internal_text_pattern_compare(arg1, arg2);
PG_FREE_IF_COPY(arg1, 0);
PG_FREE_IF_COPY(arg2, 1);
PG_RETURN_INT32(result);
}
/*-------------------------------------------------------------
* byteaoctetlen
*