Chapter 49. Logical Decoding
Table of Contents
- 49.1. Logical Decoding Examples
- 49.2. Logical Decoding Concepts
- 49.3. Streaming Replication Protocol Interface
- 49.4. Logical Decoding SQL Interface
- 49.5. System Catalogs Related to Logical Decoding
- 49.6. Logical Decoding Output Plugins
- 49.7. Logical Decoding Output Writers
- 49.8. Synchronous Replication Support for Logical Decoding
PostgreSQL provides infrastructure to stream the modifications performed via SQL to external consumers. This functionality can be used for a variety of purposes, including replication solutions and auditing.
Changes are sent out in streams identified by logical replication slots.
The format in which those changes are streamed is determined by the output
plugin used. An example plugin is provided in the PostgreSQL distribution.
Additional plugins can be
written to extend the choice of available formats without modifying any
Every output plugin has access to each individual new row produced
INSERT and the new row version created
UPDATE. Availability of old row versions for
DELETE depends on
the configured replica identity (see
Changes can be consumed either using the streaming replication protocol (see Section 53.4 and Section 49.3), or by calling functions via SQL (see Section 49.4). It is also possible to write additional methods of consuming the output of a replication slot without modifying core code (see Section 49.7).