FIFO Queue Problems

I'm having a race condition with a FIFO queue program that I've created...

CREATE TABLE fifo ( id serial, data varchar(100), status int4 DEFAULT 0
);

I have a program that claims a row for itself
 my $processid = $$; my $sql_update = <<EOS;   UPDATE fifo     set status=$processid   WHERE id = (SELECT min(id) FROM
fifoWHERE status=0);
 
EOS

I can then
 my $sql_get = <<EOS   SELECT data FROM fifo WHERE status=$processid
EOS

The problem occurrs when two of the processes grab the exact same row at the
exact same instant. It happens roughly 1 out of 1000 times. I'm not sure if
setting the transactions to serializable would fix the problem since it occurrs
between different postmasters.

My experience with Views and Triggers is minimal. Would they even help? Could
someone suggest a better FIFO queue method?


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