continuo-postgres-adapter

Postgres engine-adapter library for Continuo python nodes. PostgresAdapter implements continuo_engine_contract.port.WarehouseAdapter (from the continuo-engine-contract package) — one class covering both the data plane (fetch / ensure_table / load) and release-time validation (ensure_schema / drop_schema / build_empty_from_sql / build_empty_from_columns / clone_empty_from_prod / check_binds) — and registers itself under entry-point group continuo_engine.adapters as postgres.

Connection env: POSTGRES_HOST, POSTGRES_DB, POSTGRES_USER (required); POSTGRES_PORT (default 5432), POSTGRES_PASSWORD (default empty).

The connection runs with autocommit = True; every method owns its transaction explicitly. load() and ensure_table() open an explicit BEGIN around their statements and COMMIT/ROLLBACK themselves, so a mid-sequence failure leaves no partial change. fetch() executes a single read and commits (or rolls back on error), never leaving an open transaction dangling.

The config: index vocabulary is the union of the two vocabularies this adapter inherited from the merge: columns, unique, type, and name, with the strictest check from each side applied. The derived index name is built from the table and the column list only — type and unique are not folded into it, so two index entries on the same columns that differ only in type (or only in unique) collide on that derived name and are rejected as a duplicate. Give one of them an explicit name: when that is genuinely intended.

Verification tier: unit tests are mock-free pure-logic tests (type-grammar validation, Arrow table construction from rows); DDL/transactional behavior (schema/table creation, load truncate+insert+rollback, validation DDL) is verified against a live postgres:16 engine in tests/test_integration_runtime_postgres.py and tests/test_integration_postgres_validation.py.