Found this little thing by accident - this is an AMQP library for Postgres. Gives Postgres the ability to publish AMQP messages as a part of a database transaction. Not very closely related to nginn-messagebus, but helps you achieve similar goal - sending of messages integrated with db transaction.
The upcoming postgres version will finally support ‘skip locked’ feature that makes efficient queue implementation possible. This post gives some details on the feature - it has been implemented in current development tree and will be a part of the upcoming 9.5 version. Today I compiled Postgres from sources and did some successful testing - the database behaves just as it should, the following SQL is basically an atomic ‘select next unlocked row and lock it’ operation.
select * from mq_test where status='I' order by id for update skip locked limit 1;I hope to have the implementation tested and ready before v9.5 of Postgres is released - hopefully this will happen in next few months.