Internal schema

Overview

All tool state lives in a dedicated _smplcty_schema_flow PostgreSQL schema, completely separate from user objects. User-defined objects go into whatever schema you configure via pgSchema (default: public).

Tables

_smplcty_schema_flow.history

File tracking table. Records which schema files have been applied.

Column	Type	Description
file_path	text (PK)	Relative path to the schema file
file_hash	text	SHA-256 hash of file contents
phase	text	pre, schema, or post
applied_at	timestamptz	When the file was last applied

A file is re-run only when its hash changes. There is no one-shot vs. repeatable distinction.

_smplcty_schema_flow.expand_state

Tracks in-progress expand/contract column migrations.

_smplcty_schema_flow.snapshots

Stores migration snapshots for rollback. Each snapshot captures the operations that were applied.

Why a separate schema?

• No collisions — Tool tables never conflict with user-defined objects, even if you have a table named history or snapshots
• Clean uninstall — DROP SCHEMA _smplcty_schema_flow CASCADE removes all tool state without touching user data
• Clear ownership — _smplcty_schema_flow.* is always tool-managed; everything in the user’s schema is their declared state

Creation

The schema is created automatically on first run:

CREATE SCHEMA IF NOT EXISTS _smplcty_schema_flow;

This happens in phase 0, before any other operations.