From: PFC <lists@boutiquenumerique.com>
To: Mauro Bertoli <bertolima@yahoo.it>
To: Richard Huxton <dev@archonet.com>
Cc: pgsql-sql@postgresql.org
Subject: Re: Postgres performance
Date: Sat, 05 Mar 2005 00:20:54 +0100
Message-ID: <opsm4y44r8th1vuj@musicbox> (raw)
In-Reply-To: <20050302112456.79149.qmail@web51406.mail.yahoo.com>
References: <20050302112456.79149.qmail@web51406.mail.yahoo.com>
> 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...
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To: pgsql-sql@postgresql.org
Cc: lists@boutiquenumerique.com, bertolima@yahoo.it, dev@archonet.com
Subject: Re: Postgres performance
In-Reply-To: <opsm4y44r8th1vuj@musicbox>
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