Throughput is less of an issue then queue size—Postgres can handle a truly incredible amount of throughput as long as the jobs table is small enough that it can safely remain in memory for every operation. We can handle 800k jobs/hr with postgres, but if you have more than 5k or 10k jobs in the table at any given time, you're in dangerous territory. It's a different way of thinking about queue design then some other systems, but it's definitely worth it if you're interested in the benefits Postgres can bring (atomicity, reliability, etc)