| From: | Bruce Momjian <bruce(at)momjian(dot)us> |
|---|---|
| To: | Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com> |
| Cc: | PostgreSQL Hackers <pgsql-hackers(at)postgresql(dot)org>, Robert Haas <robertmhaas(at)gmail(dot)com>, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
| Subject: | Re: patch: fix performance problems with repated decomprimation of varlena values in plpgsql |
| Date: | 2011-03-10 23:19:47 |
| Message-ID: | 201103102319.p2ANJlk21274@momjian.us |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
What happened with this patch? Alvaro saw a 25x speedup.
---------------------------------------------------------------------------
Pavel Stehule wrote:
> Hello
>
> this patch remove a multiple detoasting of varlena values in plpgsql.
>
> It is usable mainly for iteration over longer array directly loaded
> from relation.
>
> It's doesn't have a impact on semantic or behave - it's just eliminate
> some performance trap.
>
> sample: table 10000 rows one column with array with 1000 string fields:
>
> patched pl time: 6 sec
> unpatched pl time: 170 sec
>
> This doesn't change my opinion on FOR-IN-ARRAY cycle (is still
> important for readability) - just remove one critical performance
> issue
>
> Regards
>
> Pavel Stehule
[ Attachment, skipping... ]
>
> --
> Sent via pgsql-hackers mailing list (pgsql-hackers(at)postgresql(dot)org)
> To make changes to your subscription:
> http://www.postgresql.org/mailpref/pgsql-hackers
--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com
+ It's impossible for everything to be true. +
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Tom Lane | 2011-03-10 23:25:34 | Re: Indent authentication overloading |
| Previous Message | Bruce Momjian | 2011-03-10 23:15:01 | Re: Indent authentication overloading |