Thread: What is pg_toast_temp_* in my DB?

What is pg_toast_temp_* in my DB?

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Date: Tue, 4 Jan 2011 15:53:30 +0600
Subject: [GENERAL] What is pg_toast_temp_* in my DB?
From: rummandba@gmail.com
To: pgsql-general@postgresql.org

What is pg_toast_temp_* in my DB?

Hello!

pg_toast_temp_* are some special schemas where temporary tables are created.
Having special schemas for temporary tables allows low-level code to recognize such tables as temp ones, so we have many optimizations.
I believe that in the documentation there's more explanations about it.

Regards,
Andre Fernandes.

On Tuesday 04 January 2011 3:04:29 am André Fernandes wrote:
> Date: Tue, 4 Jan 2011 15:53:30 +0600
> Subject: [GENERAL] What is pg_toast_temp_* in my DB?
> From: rummandba@gmail.com
> To: pgsql-general@postgresql.org
>
> What is pg_toast_temp_* in my DB?
>
> Hello!
>
> pg_toast_temp_* are some special schemas where temporary tables are
> created. Having
>  special schemas for temporary tables allows low-level code to recognize
>  such tables as temp ones, so we have many optimizations.
> I believe that in the documentation there's more explanations about it.
>
> Regards,
> Andre Fernandes.

To get technical, temporary tables are put in pg_temp_* And per the release
notes for 8.3:

Place temporary tables' TOAST tables in special schemas named pg_toast_temp_nnn
(Tom)

This allows low-level code to recognize these tables as temporary, which enables
various optimizations such as not WAL-logging changes and using local rather
than shared buffers for access. This also fixes a bug wherein backends
unexpectedly held open file references to temporary TOAST tables.

--
Adrian Klaver
adrian.klaver@gmail.com