Re: Query too slow - Mailing list pgsql-performance

From Stephan Szabo
Subject Re: Query too slow
Date
Msg-id 20030826084326.M30963-100000@megazone.bigpanda.com
Whole thread Raw
In response to Re: Query too slow  (Ang Chin Han <angch@bytecraft.com.my>)
Responses Re: Query too slow
List pgsql-performance
On Tue, 26 Aug 2003, Ang Chin Han wrote:

> Stephan Szabo wrote:
>
> > Looking at the explain:
>
> Veering aside a bit, since we usually pinpoint performance problems by
> looking at EXPLAIN ANALYZE's differences between the planner's
> estimation and actual execution's stats, what's involved in parsing the
> EXPLAIN ANALYZE results, and highlighting the places where they are way
> different? Bold, underline, or put some asterisks in front of those steps.

The hardest part is determining where it matters I think.  You can use the
row counts as the base for that, but going from 1 row to 50 is not
necessarily going to be an issue, but it might be if a nested loop is
chosen.


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