Re: Repeated Query is much slower in PostgreSQL8.2.4 than DB2 9.1 - Mailing list pgsql-performance

From Mike Ivanov
Subject Re: Repeated Query is much slower in PostgreSQL8.2.4 than DB2 9.1
Date
Msg-id 4A5E5A44.5040503@activestate.com
Whole thread Raw
In response to Re: Repeated Query is much slower in PostgreSQL8.2.4 than DB2 9.1  (ning <mailxiening@gmail.com>)
Responses Re: Repeated Query is much slower in PostgreSQL8.2.4 than DB2 9.1
List pgsql-performance
ning wrote:
> The log is really long,

Which usually signals a problem with the query.

> but I compared the result of "explain analyze"
> for first and later executions, except for 3 "time=XXX" numbers, they
> are identical.
>

They are supposed to be identical unless something is really badly broken.

> I agree with you that PostgreSQL is doing different level of caching,
> I just wonder if there is any way to speed up PostgreSQL in this
> scenario,
>

This is what EXPLAIN ANALYZE for. Could you post the results please?

Cheers,
Mike


pgsql-performance by date:

Previous
From: "Haszlakiewicz, Eric"
Date:
Subject: Re: CREATE USER command slows down when user count per server reaches up to 500 000
Next
From: Andres Freund
Date:
Subject: Re: Repeated Query is much slower in PostgreSQL8.2.4 than DB2 9.1