pglogical 3.7 v3.7.26

The pglogical 3.7 extension provides logical streaming replication for PostgreSQL, using a publish/subscribe model. It is based on technology developed as part of the BDR3 project.

We use the following terms to describe data streams between nodes:

• Nodes - PostgreSQL database instances
• Providers and Subscribers - roles taken by Nodes
• Replication Set - a collection of tables

These terms have been deliberately reused from the earlier Slony technology.

pglogical is new technology utilizing the latest in-core features, so we require both provider and subscriber nodes to run PostgreSQL 10 or newer.

Use cases supported are:

• Upgrades between major versions (given the above restrictions)
• Full database replication
• Selective replication of sets of tables using replication sets
• Selective replication of table rows at either provider or subscriber side (row_filter)
• Selective replication of table columns at provider side
• Data gather/merge from multiple upstream servers

Architectural details:

• pglogical works on a per-database level, not whole server level like physical streaming replication
• One Provider may feed multiple Subscribers without incurring additional disk write overhead
• One Subscriber can merge changes from several origins and detect conflict between changes with automatic and configurable conflict resolution (some, but not all aspects required for multi-master).
• Cascading replication is implemented in the form of changeset forwarding.