From: Tom Lane <tgl@sss.pgh.pa.us>
To: Atesz <atesz@ritek.hu>
Cc: pgsql-performance@postgresql.org
Subject: Re: ACCESS EXCLUSIVE lock
Date: Wed, 18 Oct 2006 12:56:07 -0400
Message-ID: <27872.1161190567@sss.pgh.pa.us> (raw)
In-Reply-To: <4536391E.7040604@ritek.hu>
References: <4536391E.7040604@ritek.hu>
Atesz <atesz@ritek.hu> writes:
> My question: Why need this strict locking?
> In my opinion there isn't exclusion between the DROP CONSTRAINT and the
> SELECT.
This isn't going to be changed, because the likely direction of future
development is that the planner will start making use of constraints
even for SELECT queries. This means that a DROP CONSTRAINT operation
could invalidate the plan of a SELECT query, so the locking will be
essential.
regards, tom lane
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To: pgsql-performance@postgresql.org
Cc: tgl@sss.pgh.pa.us, atesz@ritek.hu
Subject: Re: ACCESS EXCLUSIVE lock
In-Reply-To: <27872.1161190567@sss.pgh.pa.us>
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