Re: Please Help: PostgreSQL performance Optimization

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От Andrew Lazarus
Тема Re: Please Help: PostgreSQL performance Optimization
Дата
Msg-id 43C6A31F.3010007@pillette.com
обсуждение исходный текст
Ответ на Re: Please Help: PostgreSQL performance Optimization  (Jamal Ghaffour <Jamal.Ghaffour@elios-informatique.fr>)
Ответы Re: Please Help: PostgreSQL performance Optimization
Список pgsql-performance
Jamal Ghaffour wrote:

>>CREATE TABLE cookies (
>>    domain varchar(50) NOT NULL,
>>    path varchar(50) NOT NULL,
>>    name varchar(50) NOT NULL,
>>    principalid varchar(50) NOT NULL,
>>    host text NOT NULL,
>>    value text NOT NULL,
>>    secure bool NOT NULL,
>>    timestamp timestamp with time zone NOT NULL DEFAULT
>>CURRENT_TIMESTAMP+TIME '04:00:00',
>>    PRIMARY KEY  (domain,path,name,principalid)
>>)
[snip]
>>SELECT path, upper(name) AS name, value FROM cookies  WHERE timestamp<CURRENT_TIMESTAMP AND
principalid='192.168.8.219'AND  
>>secure=FALSE AND (domain='ping.icap-elios.com' OR domain='.icap-elios.com')

I think the problem here is that the column order in the index doesn't
match the columns used in the WHERE clause criteria. Try adding an index
on (domain,principalid) or (domain,principalid,timestamp). If these are
your only queries, you can get the same effect by re-ordering the
columns in the table so that this is the column order used by the
primary key and its implicit index.

You should check up on EXPLAIN and EXPLAIN ANALYZE to help you debug
slow queries.

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