hesela.devLogical decoding
Logical decoding reconstructs database changes from a storage-level log into a representation that a consumer can interpret without the database's physical storage format.
PostgreSQL uses output plugins to translate WAL into change streams. A logical slot serves one database and has its own progress state. [1] A disconnected slot can retain system-catalog row versions needed for decoding, so monitoring only retained WAL misses part of its resource footprint. [1]
Relations
- related
- replication-slot, write-ahead-log, log-sequence-number, idempotency
Limitations
- After a crash, checkpointed slot progress can rewind and recent changes can be delivered again; consumers must prevent duplicate effects. [1]