Emmett, an Event Sourcing library for Node.js, now supports PostgreSQL as an event store backend via the new @event-driven-io/emmett-postgresql package. It uses node-postgres with connection pooling and introduces inline projections — read model updates that run in the same transaction as event appends. The integration leverages Pongo (a MongoDB-compatible API layer on top of PostgreSQL) for document storage, supporting single-stream and multi-stream projection patterns. The author also details recent Pongo improvements including new document manipulation methods, external connection pool injection for transaction support, and a schema change from UUID to TEXT for document IDs to enable stream ID reuse.
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