Re: temporary tables are logged somehow? - Mailing list pgsql-general

From Tom Lane
Subject Re: temporary tables are logged somehow?
Date
Msg-id 23653.1421941466@sss.pgh.pa.us
Whole thread Raw
In response to Re: temporary tables are logged somehow?  (Michael Paquier <michael.paquier@gmail.com>)
Responses Re: temporary tables are logged somehow?
List pgsql-general
Michael Paquier <michael.paquier@gmail.com> writes:
> On Thu, Jan 22, 2015 at 11:06 PM, Andrey Lizenko <lizenko79@gmail.com> wrote:
>> 3. They are not WAL-logged.
>> Whats wrong with it in my case?

> Nothing. Temporary tables are not WAL-logged, but transaction commit is.

Right.  I think there is some optimization for transactions that only
wrote temp-table data, but it could at most be skipping fsync of the
transaction commit record, not omitting generating it entirely.

Also, changes to the system catalogs are always WAL-logged; so creation
and deletion of a temp table cause some amount of WAL output, even if
manipulation of the table's contents does not.

            regards, tom lane


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