Logical replication allows us to stream logical data changes between two nodes. By logical, we mean streaming changes to data without referring to specific physical attributes such as a block number and row ID.
The main benefits of logical replication are as follows:
- Performance is roughly two times better than that of the best trigger-based mechanisms
- Selective replication is supported, so we don't need to replicate the entire database (only available with pglogical at present)
- Replication can occur between different major releases, which can allow a zero-downtime upgrade
PostgreSQL 9.4 onwards provides a feature called logical decoding. This allows you to stream a set of changes out of a master server. This allows a master to become a sending node in logical replication. The receiving node requires a logical replication plugin to allow replication...
