Database Migration Tutorial

Introduction

This tutorial guides you through a basic PostgreSQL database migration process. It covers initial setup and a simple example migration.

Migration involves creating a new database or schema, and then migrating existing data.

Steps

1. **Create a New Database:** Start by creating a new database. 2. **Create a Schema:** Create a schema within the new database. 3. **Create a Migration File:** Create a migration file that defines the data and schema changes to be applied. 4. **Apply the Migration:** Execute the migration file to apply the changes. 5. **Verify the Migration:** Check the database to confirm the changes were applied correctly.

Example Migration (Simplified)

Let's create a simple table and migrate it to a new database.

We'll create a new database named 'migration_db' and a schema named 'my_schema'.

1. **Create Migration File (migration.sql):** ```sql CREATE TABLE my_schema.my_table ( id SERIAL PRIMARY KEY, name VARCHAR(255), value INTEGER ); ```

2. **Execute Migration (migration.sql):** ```bash psql -U postgres -d migration_db -f migration.sql ```

3. **Verify Migration (migration.sql):** Connect to the 'migration_db' database and verify the new table `my_schema.my_table` exists.

Conclusion

This initial example illustrates the basic process. More complex migrations might involve data validation, error handling, and testing.