[mojuba]

> Instead of SELECT FOR UPDATE followed by UPDATE, just UPDATE with a LIMIT, and then see if any rows were affected

Should be noted, this is not necessarily a good solution: a concurrent consumer, which may be another incarnation of a given script running with a lag, may hijack the queue element locked this way; as a result you may end up having two or more incarnations of the consumer handling the same queue element.

The most universal approach to DB queues is to assign each consumer process a unique ID which it should use for locking queue elements in their UPDATE ... LIMIT 1.

[Limes102]

I agree. I set a process identifier and the time of the update.