Re: replace_text() improvement

Your patch has been added to the PostgreSQL unapplied patches list at:

http://momjian.postgresql.org/cgi-bin/pgpatches

It will be applied as soon as one of the PostgreSQL committers reviews
and approves it.

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Atsushi Ogawa wrote:
>
> I made the patch that improved the performance of replace_text().
> The content of the patch is as follows:
>
> (1)Create shortcut when subtext was not found.
>
> (2)Stop using LEFT and RIGHT macro.
> In LEFT and RIGHT macro, TEXTPOS is executed by the same content as
> execution immediately before. The execution frequency of TEXTPOS can be
> reduced by using text_substring instead of LEFT and RIGHT macro.
>
> (3)Add appendStringInfoText, and use it instead of appendStringInfoString.
> There is an overhead of PG_TEXT_GET_STR when appendStringInfoString is
> executed by text type. This can be reduced by appendStringInfoText.
>
> (4)Reduce execution of TEXTDUP.
>
> The effect of the patch that I measured is as follows:
>
> - The Data for test was created by 'pgbench -i'.
>
> - Test SQL:
> select replace(aid, '9', 'A') from accounts;
>
> - Test results: Linux(CPU: Pentium III, Compiler option: -O2)
> original: 1.515s
> patched: 1.250s
>
> regards,
>
> ---
> Atsushi Ogawa

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