Re: newly created database makes queries run 300% faster - Mailing list pgsql-performance

From Brad Nicholson
Subject Re: newly created database makes queries run 300% faster
Date
Msg-id 44A536D3.10601@ca.afilias.info
Whole thread Raw
In response to newly created database makes queries run 300% faster  ("Ksenia Marasanova" <ksenia.marasanova@gmail.com>)
List pgsql-performance
Ksenia Marasanova wrote:
> Hi,
>
> Alfter hours of adjusting performance of the queries in my Postgres
> 7.3 database - reprogramming the queries, VACUUMing, changing value of
> enable_seqscan - I gived it up, recreated the database and transferred
> the dump of the old database into it.
> The queries went from 15 sec to 50 msec!! Wow.
> Now I would really love to know how the old database got that slow,
> and how can I avoid it in the future. Any tips are greatly
> appreciated!

If memory servers me (and it might not in this case), vacuum in 7.3 had
issues with indexes.  Reindexing or clustering your tables might have
helped.  Both are blocking operations.

How to avoid it in the future is simple.  Upgrade to a modern version of
Postgres and vacuum your database properly.  People work on this thing
for a reason :-)


--
Brad Nicholson  416-673-4106
Database Administrator, Afilias Canada Corp.


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