Execution phases

Operations execute in strict dependency order. This ensures PostgreSQL dependencies are satisfied (extensions before enums, enums before tables, tables before indexes, etc.).

Phase	Object type	Notes
0	Internal schema	CREATE SCHEMA IF NOT EXISTS _smplcty_schema_flow
0+	Prechecks	Pre-migration assertions (abort if falsy)
1	Pre-scripts	SQL in pre/, alphabetical order
2	Extensions	CREATE EXTENSION IF NOT EXISTS
3	Enums	CREATE TYPE ... AS ENUM, ALTER TYPE ... ADD VALUE
4	Roles	CREATE ROLE, ALTER ROLE, GRANT membership
5	Functions	CREATE OR REPLACE FUNCTION
6	Tables	CREATE TABLE, ALTER TABLE (columns, checks, unique) — without FKs
7	Indexes	Created outside transaction using CONCURRENTLY
8	Foreign keys	Added as NOT VALID, then validated separately
9	Views	CREATE OR REPLACE VIEW
10	Materialized views	CREATE MATERIALIZED VIEW, REFRESH
11	Triggers	CREATE TRIGGER
12	RLS policies	ENABLE ROW LEVEL SECURITY, CREATE POLICY
13	Grants	GRANT/REVOKE on tables, columns, sequences, functions, schemas
14	Comments	COMMENT ON for all object types
15	Seeds	INSERT ... ON CONFLICT
16	Post-scripts	SQL in post/, alphabetical order

Transaction boundaries

• Phases 0-6 and 8-16 run within a transaction (atomic commit or rollback)
• Phase 7 (indexes) runs outside the transaction because CREATE INDEX CONCURRENTLY cannot run inside a transaction
• If any transactional phase fails, all changes in that transaction roll back

Operation types

Tables & columns

create_table, drop_table, add_column, alter_column, drop_column

Indexes

add_index, add_unique_index, drop_index

Constraints

add_check, add_check_not_valid, drop_check, add_foreign_key, add_foreign_key_not_valid, validate_constraint, drop_foreign_key, add_unique_constraint, drop_unique_constraint

Enums

create_enum, add_enum_value, remove_enum_value

Functions

create_function

Triggers

create_trigger, drop_trigger

RLS

enable_rls, disable_rls, create_policy, drop_policy

Views

create_view, drop_view, create_materialized_view, drop_materialized_view, refresh_materialized_view

Extensions

create_extension, drop_extension

Roles & grants

create_role, alter_role, grant_membership, grant_table, grant_column, revoke_table, revoke_column, grant_sequence, revoke_sequence, grant_function, revoke_function, grant_schema

Expand/contract

expand_column, create_dual_write_trigger, backfill_column, contract_column, drop_dual_write_trigger

Schema

create_schema

Other

set_comment, add_seed, run_precheck