Re: table level locking different in 7.0?

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Jim Mercer <jim(at)reptiles(dot)org>
Cc: pgsql-hackers(at)postgresql(dot)org
Subject: Re: table level locking different in 7.0?
Date: 2000-05-18 00:19:36
Message-ID: 19586.958609176@sss.pgh.pa.us
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Jim Mercer <jim(at)reptiles(dot)org> writes:
> i had several concurrent processes which would do inserts via COPY and
> queries.
> on that system, i don't recall the COPY processes as being blocked by the
> query processes.
> now i'm running that app on solaris 7 with pgsql 7.0.
> i'm finding that a big long select is blocking other processes which
> are doing COPY's.

Hmm. In 7.0, COPY IN acquires an exclusive lock on the target table,
which is something I put in in a fit of paranoia. It may not really
be necessary --- probably a regular write lock would be good enough.
(6.5's COPY code neglected to acquire any lock at all, which is surely
*not* good enough, but maybe I overreacted.)

Comments anyone?

regards, tom lane

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