Each source PostgreSQL database relies upon its logical decoding feature. In PostgreSQL, logical decoding is implemented by decoding the contents of the Write Ahead Log (WAL) files. The WAL files contain information about the history of activity on a database, and Datastream leverages these files to query data changes. For more information about how Datastream works with WAL files, see Work with PostgreSQL database WAL files.
Datastream works with the following types of PostgreSQL databases:
- AlloyDB for PostgreSQL
- AlloyDB Omni
- Amazon Aurora PostgreSQL
- Amazon RDS for PostgreSQL
- Cloud SQL for PostgreSQL
- Self-managed PostgreSQL (on-premise or cloud-hosted)
For information about how to configure and verify that logical decoding is enabled for each of these database types, see their respective pages.