From: Tom Lane <tgl@sss.pgh.pa.us>
To: Ross J. Reedstrom <reedstrm@wallace.ece.rice.edu>
Cc: Gary Stainburn <gary.stainburn@ringways.co.uk>
Cc: 'Pgsql Interfaces' <pgsql-interfaces@postgreSQL.org>
Subject: Re: [INTERFACES] locking on database updates
Date: Tue, 07 Dec 1999 12:59:33 -0500
Message-ID: <23996.944589573@sss.pgh.pa.us> (raw)
In-Reply-To: <19991207111234.A6021@rice.edu>
"Ross J. Reedstrom" <reedstrm@wallace.ece.rice.edu> writes:
> create table foo (bar serial, baz text);
> insert into foo (baz) values ('wooble');
> select currval('foo_bar_seq');
I don't think this is safe in a multi-client environment;
what if someone else inserts at about the same time?
Better to do
select nextval('foo_bar_seq');
insert into foo values (just-retrieved-value, 'wooble');
which is safer and probably marginally faster (since the
sequence object is touched only once, not twice).
regards, tom lane
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To: pgsql-interfaces@postgresql.org
Cc: tgl@sss.pgh.pa.us, reedstrm@wallace.ece.rice.edu, gary.stainburn@ringways.co.uk
Subject: Re: [INTERFACES] locking on database updates
In-Reply-To: <23996.944589573@sss.pgh.pa.us>
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