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help / color / mirror / Atom feedFrom: Tom Lane <tgl@sss.pgh.pa.us>
To: David G. Johnston <david.g.johnston@gmail.com>
Cc: Siraj G <tosiraj.g@gmail.com>
Cc: Scott Ribe <scott_ribe@elevated-dev.com>
Cc: Pgsql-admin <pgsql-admin@lists.postgresql.org>
Subject: Re: Does export operation cancel SQLs?
Date: Wed, 19 Feb 2025 17:27:45 -0500
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"David G. Johnston" <david.g.johnston@gmail.com> writes:
> On Wed, Feb 19, 2025 at 1:57 PM Siraj G <tosiraj.g@gmail.com> wrote:
>> But I wonder if pg_dump does acquire locks?
> Everything acquires locks (basically). It is the specific nature of the
> locks held and requested that matter.
For more color on that see
https://www.postgresql.org/docs/current/explicit-locking.html#LOCKING-TABLES
particularly the table of lock mode conflicts. pg_dump generally
takes ACCESS SHARE locks on the tables it plans to dump, which is
the same lock level taken by a plain SELECT. That will only
block ACCESS EXCLUSIVE locks, which by and large are only taken
by major DDL operations.
regards, tom lane
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Subject: Re: Does export operation cancel SQLs?
In-Reply-To: <2583155.1740004065@sss.pgh.pa.us>
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