How to Use PostgreSQL LISTEN/NOTIFY for Live Updates Without Extra Infrastructure

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PostgreSQL includes a built-in pub/sub mechanism called LISTEN/NOTIFY that allows apps to push live updates to connected clients without needing Redis or a separate message broker. One session triggers pg_notify on a channel, and any session actively listening on a persistent connection receives the payload once the transaction commits. Key limitations include an 8,000-byte payload cap, 63-character channel name limit, and no message persistence or delivery guarantee, making it suitable as a change signal rather than a reliable queue. Because pooled connections get recycled, a dedicated long-lived connection that bypasses transaction-mode poolers like PgBouncer is required for LISTEN to work reliably. A single shared LISTEN connection can multiplex multiple logical channels and feed per-client Server-Sent Events streams, with careful reconnect logic needed to avoid race conditions.

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ProgrammingDEV Community ·

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ProgrammingDEV Community ·

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ProgrammingDEV Community ·

How to Connect WSL2 Python Apps to LM Studio's Local API on Windows

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