Re: table level locking different in 7.0? - Mailing list pgsql-hackers

From Tom Lane
Subject Re: table level locking different in 7.0?
Date
Msg-id 19586.958609176@sss.pgh.pa.us
Whole thread Raw
In response to table level locking different in 7.0?  (Jim Mercer <jim@reptiles.org>)
Responses Re: table level locking different in 7.0?  (Tom Lane <tgl@sss.pgh.pa.us>)
Re: table level locking different in 7.0?  (Bruce Momjian <pgman@candle.pha.pa.us>)
List pgsql-hackers
Jim Mercer <jim@reptiles.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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