Various experiments with PostgreSQL clustering perfomed at PostgresPro.

This is a mirror of postgres repo with several changes to the core and a few extra extensions.

• Transaction manager interface (eXtensible Transaction Manager, xtm). Generic interface to plug distributed transaction engines. More info on postgres wiki and on the email thread.
• Distributed deadlock detection API.
• Logical decoding of transactions.

A distributed transaction management daemon. Used by pg_dtm and multimaster.

A synchronous multi-master replication based on logical decoding and xtm.

A synchronous multi-master replication based on snapshot sharing.

A coordinator-based distributed transaction management implementation based on snapshot sharing.

A coordinator-less distributed transaction management implementation based on commit timestamps.

A key-value table replicated over Raft protocol. Used by mmts.