Updating Grid Database Schema
Occasionally, the Grid database schema may need to be updated with new or modified tables. These changes are made by adding new migrations files for each Grid-supported database backend.
New migrations can be generated by navigating to the
sdk/src/migrations/diesel/<backend> directory for the backend the migration
is for and running the command:
$ diesel migration generate $NEW_MIGRATION_NAME
Migrations consist of two files,
contains the database commands to run the required updates while the
file reverses those same changes.
When adding new migrations it is a good idea to test that the migrations run successfully. To run the migrations, start the Grid database for the appropriate backend and use the command:
$ grid database migrate
New migrations should take care when updating tables not to delete any data
unintentionally. For example, adding a column to a table by dropping it and
adding the updated table would update the schema but could result in data loss
for a user updating their own system. Instead,
ALTER TABLE commands should be
used where possible.