Обсуждение: Full vacuum really slowing query down

I have a query that takes 2.5 sec if I run it from a freshly restored
dump.  If I run a full vacuum on the database it then takes 30 seconds.

Would someone please comment as to why I would see over a 10x slow down
by only vacuuming the DB?

I am using 8.3.1

On 2008-06-04 23:18, Jason Long wrote:

> I have a query that takes 2.5 sec if I run it from a freshly restored
> dump.  If I run a full vacuum on the database it then takes 30 seconds.

1. Don't run "vacuum full", run plain "vacuum". If you run "vacuum full"
then "reindex" afterwards.

2. Run "analyze".

3. Please provide a description of your tables - schemas, how much data
there.

4. Please provide your query.

5. Please provide an output of "explain analyze [your_query]".

Regards
Tometzky
--
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