Re: Correct usage of FOR UPDATE?

Hello,

I have a simple table-based queue system, and I'd looking for some advice on improving my dequeue function. it boils down to:

SELECT id

FROM queue

WHERE <whereclause>

FOR UPDATE NOWAIT;

which works well, in that no item gets dequeued more that once. The issue, however is that when a contention occurs, the error "could not obtain lock on row in relation" is raised. 

Is there a way that I can rewrite this so that when a contention occurs, there is no error? I would like the "winning" process to lock the row, and the "losing" process to select null rather than raise the rowlock error.

thanks beforehand for any help!