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Re: DELETE versus TRUNCATE during pg_dump.... - Mailing list pgsql-general

From Christopher Browne
Subject Re: DELETE versus TRUNCATE during pg_dump....
Date
Msg-id 60is6vbcrj.fsf@dba2.int.libertyrms.com
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In response to DELETE versus TRUNCATE during pg_dump....  (Patrick Hatcher <pathat@comcast.net>)
List pgsql-general
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pathat@comcast.net (Patrick Hatcher) writes:
> Curious:  Why would a DELETE FROM tablename work while a pg_dump is
> occurring but a TRUNCATE tablename will stay in a lock state until the
> pg_dump is complete?

DELETE FROM merely has to mark all the tuples as dead, which requires
no control over the table as a whole.

TRUNCATE essentially reinitializes the table as empty, which does need
a (if brief) lock on the table.

Yeah, you can't TRUNCATE while the dump is running...
--
"cbbrowne","@","ca.afilias.info"
<http://dev6.int.libertyrms.com/>
Christopher Browne
(416) 673-4124 (land)

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