PostgreSQL

The warehouse and the backbone of the control plane. One instance, multiple schemas, responsible for platform state plus analytics data.

Tier

Hot. PostgreSQL is part of the base install and stays running at all times. Expected memory: ~800 MB–1.2 GB depending on warehouse size.

Role

Everything writable lands here. The same PostgreSQL instance holds:

• Platform state — user accounts, roles, permissions, sessions, audit log.
• Warehouse raw — landed data from Airbyte, awaiting dbt.
• Warehouse marts — dbt outputs served to Metabase.
• Service metadata — Airflow's DAG state, OpenMetadata's catalogue (when enabled).

Each concern gets its own schema. Separation makes permissions cleaner without adding operational complexity.

Schema layout

platform       -- users, roles, sessions, audit
raw            -- Airbyte-landed tables, one per source
marts          -- dbt outputs: fct_*, dim_*, stg_*
airflow        -- Airflow's internal metadata tables
openmetadata   -- OpenMetadata's internal tables (if enabled)

Configuration

Credentials are collected at install time:

• POSTGRES_USER — superuser for platform management
• POSTGRES_PASSWORD — bcrypt-stored as platform password; stored plain in .env for Postgres
• POSTGRES_DB — default database name (typically OrcheStack)

OrcheStack creates per-service PostgreSQL roles with scoped privileges so each downstream tool (dbt, Airflow, Metabase) authenticates as its own user with only the permissions it needs.