Event Store Schema Overview

Purpose: Append-only log of domain events. No ad-hoc querying; projections handle reads.

Columns

• global_seq: Monotonic PK (BIGINT; PG identity)
• event_id: ULID (26 chars), unique
• stream_id, stream_type: stream identity
• version: optimistic concurrency per stream
• payload: event body (JSON/JSONB)
• metadata: transport/trace info (JSON/JSONB)
• recorded_at: UTC timestamp (server default)

Constraints enforced here

• ULID length == 26
• UNIQUE(stream_id, version)
• UNIQUE(event_id)
• version >= 1

See ADR-0005 for rationale and tradeoffs.