deb-sahara/sahara/db/migration/alembic_migrations/README.md

The migrations in alembic_migrations/versions contain the changes needed to migrate between Sahara database revisions. A migration occurs by executing a script that details the changes needed to upgrade the database. The migration scripts are ordered so that multiple scripts can run sequentially. The scripts are executed by Sahara's migration wrapper which uses the Alembic library to manage the migration. Sahara supports migration from Icehouse or later.

You can upgrade to the latest database version via:

$ sahara-db-manage --config-file /path/to/sahara.conf upgrade head

To check the current database version:

$ sahara-db-manage --config-file /path/to/sahara.conf current

To create a script to run the migration offline:

$ sahara-db-manage --config-file /path/to/sahara.conf upgrade head --sql

To run the offline migration between specific migration versions:

$ sahara-db-manage --config-file /path/to/sahara.conf upgrade <start version>:<end version> --sql

Upgrade the database incrementally:

$ sahara-db-manage --config-file /path/to/sahara.conf upgrade --delta <# of revs>

Create new revision:

$ sahara-db-manage --config-file /path/to/sahara.conf revision -m "description of revision" --autogenerate

Create a blank file:

$ sahara-db-manage --config-file /path/to/sahara.conf revision -m "description of revision"

This command does not perform any migrations, it only sets the revision. Revision may be any existing revision. Use this command carefully.

$ sahara-db-manage --config-file /path/to/sahara.conf stamp <revision>

To verify that the timeline does branch, you can run this command:

$ sahara-db-manage --config-file /path/to/sahara.conf check_migration

If the migration path does branch, you can find the branch point via:

$ sahara-db-manage --config-file /path/to/sahara.conf history