Re: like performance w/o wildcards. - Mailing list pgsql-general

From Tom Lane
Subject Re: like performance w/o wildcards.
Date
Msg-id 22747.1060096932@sss.pgh.pa.us
Whole thread Raw
In response to Re: like performance w/o wildcards.  ("scott.marlowe" <scott.marlowe@ihs.com>)
List pgsql-general
"scott.marlowe" <scott.marlowe@ihs.com> writes:
>>> It does ... if the index-conversion optimization is enabled at all.
>>
>> Sorry, what is 'index-conversion optimization' and when is it enabled?

> I don't know what that is either.  Tom?

Sorry, I just meant the code that tries to extract indexable conditions
from a LIKE clause.  With a fixed-prefix pattern, eg "x LIKE 'foo%'",
you get a range condition like "x >= 'foo' AND x < 'fop'".  For a
completely fixed pattern this degenerates to "x = 'foo'".  The whole
thing turns off in non-C locales though.

            regards, tom lane

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