Schemachange

Deploy and manage Snowflake database changes using version control and CI/CD pipelines with schemachange's migration-based approach.

Quick Start

Script Types:

• V\\ (Versioned) - One-time structural changes (run exactly once)
• R\\ (Repeatable) - Objects that can be safely recreated (runs when new/modified)
• A\\ (Always) - Scripts that run every deployment (must be idempotent)

Script Naming

Versioned Scripts (V\\)

V1.0.0__initial_setup.sql
V1.1.0__create_base_tables.sql
V2.0.0__restructure_schema.sql

Use for: CREATE TABLE, ALTER TABLE, CREATE SCHEMA

Repeatable Scripts (R\\)

R__Stage_01_create_views.sql
R__Stage_02_alter_procedures.sql
R__Stage_03_utility_functions.sql

Use for: CREATE OR ALTER VIEW, CREATE OR ALTER PROCEDURE, CREATE OR REPLACE STREAM

Always Scripts (A\\)

A__refresh_permissions.sql
A__update_config_values.sql

Use for: Jobs that must run every deployment (idempotent only)

Key Concepts

Execution Order

1. Versioned scripts (V\\) in numeric order
2. Repeatable scripts (R\\) in alphabetic order (use naming to control)
3. Always scripts (A\\) in alphabetic order

CREATE OR ALTER vs CREATE OR REPLACE

• CREATE OR ALTER - Preserves data, tags, policies, grants (preferred)
• CREATE OR REPLACE - Drops and recreates (loses metadata)

See CREATEORALTER_REFERENCE.md for supported objects.

Configuration

# schemachange-config.yml
root-folder: migrations
create-change-history-table: true
connection-name: default
change-history-table: MY_DB.SCHEMACHANGE.CHANGE_HISTORY

Deployment

# Dry run
schemachange deploy --config-folder . --dry-run

# Deploy
schemachange deploy --config-folder .

# With variables
schemachange deploy --vars '{"env":"prod","schema":"data"}'

Resources

• schemachange-config.yml - Complete configuration template
• SCRIPTPATTERNS.md - Examples for V, R, A\\_ scripts (coming soon)
• CREATEORALTER_REFERENCE.md - Supported object types (coming soon)
• CICDEXAMPLES.md - GitHub Actions and Azure DevOps patterns (coming soon)