How to Synchronize Database Schemas

This tutorial will walk you through the typical use cases for database schema synchronization in Bytebase with pure UI operations. The Sync Schema feature in Bytebase supports copying a specific schema version from one database to multiple others. Without it, developers have to write SQL statements cautiously and apply them manually. Additionally, this feature may also be used for rollback purpose.

Preparation

Make sure you installed Docker.

Copy and paste the commands to start one Bytebase via Docker.

docker run --rm --init \
  --name bytebase \
  --publish 8080:8080 --pull always \
  --volume ~/.bytebase/data:/var/opt/bytebase \
  bytebase/bytebase:3.8.1

Case 1 - Sync Schema to a New Database

When you set up a new environment or find the current database is nearing capacity, it becomes necessary to establish a new database and synchronize the schema from the original database.

Go into Sample Project, there are two databases hr_test on Test environment and hr_prod on Prod environment. Let’s create another one on Prod.
Click New DB, fill in the form as follows and click Create:
- Name: hr_prod_2
- Environment: Prod
- Instance: Prod Sample Instance
- Database owner name: bbsample
An issue will be created and executed automatically, and the database hr_prod_2 will be ready when the issue is Done.
Within the project, click Sync Schema, choose hr_prod as the source schema, and click Next.
You may select as many target databases as you like to sync to. Here we select all (including the source) and click Select.
Bytebase will calculate the schema differences between the source and target databases, and generate the suggested DDL statements. Click Preview Issue.
An issue with the generated DDL is created automatically. Click Rollout ignoring the SQL review warning. After the issue execution is Done, the schema synchronization is completed.

Case 2 - Sync Schema from One to Many

During the product release process, for different environments, such as dev, staging and prod, you’ll need to do schema synchronization. Furthermore, for the prod environment, databases with identical schemas, such as SaaS, and multi-region game deployment, you may also need to sync the schema to multiple databases at the same time.

Within the project, select hr_test and click Edit Schema. With the help of Schema Editor, add a new column email as follows and click Preview issue:
- Name: email
- Type: text
- Default: Empty string
- Not Null: checked
An issue is created and executed automatically. After it’s Done, the new column email is added.
Within the project, click Sync Schema, choose hr_test as the source schema and click Next.
Select hr_prod and hr_prod_2 as the target databases. Schema differences are calculated and the suggested DDL statements are generated. Click Preview issue.
An issue with the generated DDL is created automatically. Because two databases need to be synced, there’re two task blocks. After they execute one by one, the issue is Done, and email is added.

Case 3 - Rollback to Previous Schema Versions

In Bytebase Community Plan, you can choose the latest history version; In Pro Plan or Enterprise Plan, you can choose an arbitrary schema version from the full migration history. Which means you can roll back to any previous schema version.

After upgrading to Enterprise Plan, go into Sample Project, click Sync Schema and select hr_test as the source schema. When you choose the schema version, you will see the following prompt. That’s because we haven’t assigned the enterprise license to database instances.
Click on the lock sign, select both two instances, and click Confirm.
After the license is assigned, you can choose the schema version freely, we’ll choose the previous version and click Next.
Choose the same database hr_test as the target, and click Select.
Bytebase will calculate the schema differences between the source and target databases, and generate the suggested DDL statements. Here means if you want to roll back to the previous version, you’ll need to delete this line. Click Preview Issue.
Click Create, an issue with the generated DDL is created and rollout automatically. After the issue execution is Done, the schema rolls back to the previous version.