Query performance question on a large table
От | Együd Csaba |
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Тема | Query performance question on a large table |
Дата | |
Msg-id | 000701c3d48d$26adfdc0$230a0a0a@compaq обсуждение исходный текст |
Ответы |
Re: Query performance question on a large table
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Список | pgsql-general |
Hi All, how can I improve the query performance in the following situation: I have a big (4.5+ million rows) table. One query takes approx. 9 sec to finish resulting ~10000 rows. But if I run simultaneously 4 similar queries it takes nearly 5 minutes instead of 4 times 9 seconds or something near of that. here is a sample query: select mertido, fomeazon, ertektipus, mertertek from t_me30 where fomeazon in (select distinct fomeazon from t_fome where lower(inuse) = 'igen') and mertido like '2003-12-17%' and ertektipus in ('+MW') order by mertido, fomeazon, ertektipus; What kind of indexes could speed up a query like this? I tried to create one on fields (mertido, fomeazon, ertektipus) but led me much longer execution time. Ohh, I nearly forgot the config: Linux 7.1; Postgres 7.3.2; Thank you, bye ---------------------------------------- Csaba Együd csegyud@vnet.hu
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