From: Galy Lee <lee.galy@oss.ntt.co.jp>
To: pgsql-performance@postgresql.org
Subject: Re: how to plan for vacuum?
Date: Wed, 24 Jan 2007 16:44:55 +0900
Message-ID: <45B70E77.9050102@oss.ntt.co.jp> (raw)
In-Reply-To: <45B6F0A8.1050705@oss.ntt.co.jp>
References: <45B6F0A8.1050705@oss.ntt.co.jp>
Just have one example here:
workload: run pgbench in 365x24x7
database size: 100GB
the workload distribution:
06:00-24:00 100tps
00:00-06:00 20tps
how should we plan vacuum for this situation to get the highest performance?
Best regards
Galy
Galy Lee wrote:
> Hi,
>
> For I can not find too much information about how to use vacuum, I want
> to ask some general information about the guideline of vacuum planning.
>
> 1. How do we know if autovacuum is enough for my application, or should
> I setup a vacuum manually from cron for my application?
>
> 2. How to set the GUC parameters for autovacuum?
> There are two sets of parameters for autovacuum:
> - vacuum threshold and scale factor (500/0.2)
> - analyze threshold and scale factor(250/0.1)
> Is there any guideline to set these parameters? When does it need to
> change the default values?
>
> 3. How to tune cost-based delay vacuum?
> I had searched in performance list; it seems that most of the practices
> are based on experience / trial-and-error approach to meet the
> requirement of disk utilization or CPU utilization. Is there any other
> guild line to set them?
>
> For when autovacuum is turned on by default, if the parameters for
> vacuum have not been set well, it will make the system rather unstable.
> So I just wonder if we should setup a section in the manual about the
> tips of vacuum, then many users can easily set the vacuum parameters for
> their system.
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To: pgsql-performance@postgresql.org
Cc: lee.galy@oss.ntt.co.jp
Subject: Re: how to plan for vacuum?
In-Reply-To: <45B70E77.9050102@oss.ntt.co.jp>
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