Date: Tue, 12 Nov 2019 09:44:32 +0900
From: Michael Paquier <michael@paquier.xyz>
To: analytik@uglycode.com, pgsql-docs@lists.postgresql.org
Subject: Re: Does TRUNCATE emit changes with REPLICA IDENTITY FULL?
Message-ID: <20191112004432.GB1549@paquier.xyz>
References: <157346399242.14265.3138867514991013615@wrigleys.postgresql.org>
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On Mon, Nov 11, 2019 at 09:19:52AM +0000, PG Doc comments form wrote:
> The documentation says that TRUNCATE ignores ON DELETE triggers, but it
> doesn't explicitly mention what happens if we use `wal_level = logical` and
> `REPLICA IDENTITY FULL`. Does TRUNCATE emit changes for each row and clog
> the WAL, or will it still be blazing fast?

Truncate does not issue per-row changes with a full replica identity
in this context.  It roughly just takes an exclusive lock on the
table, then physically removes all the files related to the table.
--
Michael

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