Re: table as log (multiple writers and readers) - Mailing list pgsql-general

brian wrote:

> Use a timestamp column also.

That's subject to the same issues, because a transaction's
current_timestamp() is determined at transaction start. So, in a
situation like this:


WRITER 1    WRITER 2    READER 1
--------------------------------------------
BEGIN
             BEGIN
INSERT
             INSERT
             COMMIT
                         BEGIN
                         SELECT
COMMIT

then READER 1 will see the most recent timestamp as that inserted by
WRITER 2, but it won't see the row inserted by WRITER 1 with an earlier
timestamp.

I don't think it's even OK in the case of a single-statement INSERT
(where the transaction is implicit) and/or with the use of
clock_timestamp() ... though I'm less sure about that.

--
Craig Ringer