Re: tuning tips, speed problem

On Montag, 19. Januar 2009, BRAHMA PRAKASH TIWARI wrote:
| most probabely this is due to the auto vacuum option on and if auto vacuum
| is on then the in condition of high transaction on database it slows the
| speed of the hole database.Set it off in postgres.conf and vacuum and
| reindex transactional tables manualy with in every two million
| transactions.
| like
| vacuum full <table name>;
| reindex table <table name>;

Please, a "vacuum full" should only be a measure of last resort ever.
Regular vacuum (without the "full" keyword) should always be enough.
And I don't recommend turning autovacuum off.

You might need to increase the "max_fsm_pages" setting to avoid
database bloat. The output of a database wide "vacuum verbose" should
tell you, if it is set appropriately.

And Francesco, if you say

"but on a mysql to execute a simple select with an order by the time was jus
1 or 2 seconds ... on this installation the time it's about 10 seconds or
more",

could you provide the "explain analyze"-output for those queries? This should
help analyzing your problems.

Ciao,
Thomas

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Thomas Pundt <thomas(dot)pundt(at)rp-online(dot)de> ---- http://rp-online.de/ ----