What is the Polling Publisher pattern in the context of the Transactional Outbox?

Polling Publisher is the simpler of the two common Outbox-pattern implementations: a scheduled background job periodically queries the outbox table for new, unpublished rows, publishes each one as an event to the message broker, and marks it as sent. It's easier to build than transaction-log tailing (no CDC infrastructure needed) but introduces publish latency equal to the polling interval and adds repeated read load on the database.