To: "Mauro Bertoli" <bertolima@yahoo.it>, "Richard Huxton" <dev@archonet.com>
Cc: pgsql-sql@postgresql.org
Subject: Re: Postgres performance
References: <20050302112456.79149.qmail@web51406.mail.yahoo.com>
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Date: Sat, 05 Mar 2005 00:20:54 +0100
From: PFC <lists@boutiquenumerique.com>
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> I don't require transaction because the query aren't
> complex and update a single tuple (in SELECT
> transactions are useless)

	You mean, you have no foreign keys in your database ?
	In SELECT they are definitely useful (think select for update, isolation  
level serializable...)

> - start quote -
>  You'll find inserts/updates with lots of users is
>  where PostgreSQL works
>  well compared to other systems.
> - end quote -
> Uhhmm.. this is interesting...

	pg does not lock the whole table everytime anyone wants to write in it.  
In MySQL when you run a big select, all write activity stops during that.  
If you run a big update, all activity other than this update has to wait.

> - why postgres use a new process for every query ?
> (mySQL, if I'm not wrong, use threads... I think its
> faster)

	Not for every query, for every CONNECTION.
	You are using persistant connections are you. Are you ?

> - why connection time is slower? (compared to mySQL)?

	This is of no importance as everyone uses persistent connections anyway.

> - why postgres require analyze? (mySQL, if I'm not
> wrong, don't require it)
> Yours answers will be very apreciated! Thx

	So it has a planner which knows what it's doing ;) instead of just  
guessing in the dark.

	And MySQL requires analyze too (read the docs), optimize table which  
looks like vacuum to me, and sometimes repair table...