From: Mathias Kunter <mathiaskunter@gmail.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: pgsql-docs@lists.postgresql.org
Subject: Re: random_page_cost configuration parameter
Date: Wed, 5 Jan 2022 19:27:55 +0100
Message-ID: <6bb6023b-fce3-801d-e799-8111cc317e35@gmail.com> (raw)
In-Reply-To: <1760891.1640707405@sss.pgh.pa.us>
References: <9271c072-e91d-4dc5-c0a9-197f47291671@gmail.com>
<1760891.1640707405@sss.pgh.pa.us>
Am 28.12.21 um 17:03 schrieb Tom Lane:
> Mathias Kunter <mathiaskunter@gmail.com> writes:
>> Consider the situation
>> where the randomly fetched pages are mostly (or even entirely) cached in
>> RAM, but where the sequentially fetched pages must be mostly read from
>> disk. An example for such a scenario is a database system which uses
>> RAM-cached indices.
>
> I think fooling with effective_cache_size is a better way to model
> that situation.
The default value of effective_cache_size is 4 GB. Which value should
be used instead on a system which only has 4 GB of total RAM, but still
uses RAM-cached indices?
Thank you very much for the clarification!
Best regards
Mathias Kunter
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-docs@postgresql.org
Cc: mathiaskunter@gmail.com, tgl@sss.pgh.pa.us, pgsql-docs@lists.postgresql.org
Subject: Re: random_page_cost configuration parameter
In-Reply-To: <6bb6023b-fce3-801d-e799-8111cc317e35@gmail.com>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox