Re: patch: fix performance problems with repated decomprimation of varlena values in plpgsql
| От | Pavel Stehule |
|---|---|
| Тема | Re: patch: fix performance problems with repated decomprimation of varlena values in plpgsql |
| Дата | |
| Msg-id | AANLkTik-mS5pCLA0BH9wypORwOH698=AKwFNtYEb7iE2@mail.gmail.com обсуждение исходный текст |
| Ответ на | Re: patch: fix performance problems with repated decomprimation of varlena values in plpgsql (Bruce Momjian <bruce@momjian.us>) |
| Список | pgsql-hackers |
2011/3/11 Bruce Momjian <bruce@momjian.us>: > > What happened with this patch? Alvaro saw a 25x speedup. There is not conformance about form in this patch. But there are a FOREACH statement - so if somebody uses this statement, then he will not have a problems with performance. Regards Pavel > > --------------------------------------------------------------------------- > > 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@postgresql.org) >> To make changes to your subscription: >> http://www.postgresql.org/mailpref/pgsql-hackers > > -- > Bruce Momjian <bruce@momjian.us> http://momjian.us > EnterpriseDB http://enterprisedb.com > > + It's impossible for everything to be true. + >
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