From: Scott Ribe <scott_ribe@elevated-dev.com>
To: Ron <ronljohnsonjr@gmail.com>
Cc: pgsql-admin@lists.postgresql.org
Subject: Re: need suggestion on querying big tables
Date: Tue, 6 Dec 2022 10:07:41 -0600
Message-ID: <AF5ECE5E-E6BA-41DD-B644-EB92A870736A@elevated-dev.com> (raw)
In-Reply-To: <d926084d-63a7-854b-2d8d-459d33ec7f70@gmail.com>
References: <CAJuN1jj6NQDUjbMH=n4zry10JMJEZ8bRi=j6uA-3_108-Tq9cQ@mail.gmail.com>
<d926084d-63a7-854b-2d8d-459d33ec7f70@gmail.com>
> On Dec 6, 2022, at 8:51 AM, Ron <ronljohnsonjr@gmail.com> wrote:
>
> https://www.postgresql.org/docs/11/runtime-config-query.html
>
> effective_cache_size is how much RAM a single query gets. "When setting this parameter you should consider both PostgreSQL's shared buffers".
>
> https://www.postgresql.org/docs/11/runtime-config-resource.html
>
> "a reasonable starting value for shared_buffers is 25% of the memory in your system. There are some workloads where even larger settings for shared_buffers are effective, but because PostgreSQL also relies on the operating system cache, it is unlikely that an allocation of more than 40% of RAM to shared_buffers will work better than a smaller amount."
>
> You've set effective_cache_size to 83%, when it should be at most 20%.
effective_cache_size is a hint as to how much RAM is available for the operating system file cache after all other uses are taken into account.
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-admin@postgresql.org
Cc: scott_ribe@elevated-dev.com, ronljohnsonjr@gmail.com, pgsql-admin@lists.postgresql.org
Subject: Re: need suggestion on querying big tables
In-Reply-To: <AF5ECE5E-E6BA-41DD-B644-EB92A870736A@elevated-dev.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