Use native executors with DB2 z/OS

To use the JCL executor with Liquibase on DB2 z/OS, you must set several required properties in your liquibase.properties file.

Before using the example properties file below, be sure to:

• Replace your_hostname, your_port, and your_db_name in the connection URL for your database.

• Replace your_username and your_password with the credentials for authenticating with the DB2 instance.

• Replace your_schema with the name of the DB2 schema Liquibase should use.

• Set liquibase.jcl.create.logFile to true if you would like Liquibase to create additional logs for JCL. Logs are updated for each change type.

• Replace /logs with your preferred output file path. If you do not specify a liquibase.jcl.logFilePath, logs will be written to your system’s temporary folder. However, temporary folders are not intended for long-term storage, and files stored there may be automatically removed by the operating system at any time. We recommend setting liquibase.jcl.logFilePath to a specific, persistent location to ensure logs are retained as needed.

• Set liquibase.jcl.overwrite.logFile to true if you would like Liquibase to create a new file for each changeset. In this implementation, each JCL has its own log file. Log files are named based on their changeset ID and author. For example, if you have the changeset --changeset liquibase-deployer:unload-table-1 runWith:jcl, the changeset ID is unload-table-1. If the author is liquibase-deployer, the output log file will be named unload-table-1-liquibase-deployer.log This property is set to false by default and will append to the existing log file each time unless you explicitly set it to true.

The following changelog demonstrates how to add a column to the middle of a table on DB2 z/OS. Since DB2 doesn’t allow altering column order directly, you’ll need to:

1. Unload the table's data

2. Drop the table

3. Create the table with the new column

4. Load the table's data

Each of these steps is represented by a changeset in the changelog.

Before using this changelog, make sure you’ve created the appropriate .jcl and .sql files for each step and saved them in the correct paths referenced by --include file.

Note: We support property substitution in your JCL scripts.

You can use these files if you'd like to use the example code:

• load.jcl

• unload.jcl

• create-alter.sql

• drop.sql

Once you have your liquibase.properties set up and your changelog file created, you run your changelog file to test that your operations complete successfully.

Use the example code to apply the changelog. Be sure to update your_changelog_file.

liquibase update --changelog-file=your_changelog_file

If the command is successful, you'll see:

Liquibase command 'update' was executed successfully

If there is an error you'll see:

JOB FAILED - JCL ERROR

You should also see a Liquibase update report open in a browser window with the execution details including the JCL script and generated SQL that you can use to troubleshoot any issues.