========================================== Purge data on shadow tables ========================================== The purge step is disable by default. When enabled, it will run before proceeding to actual upgrade steps. This can be enabled with the ``--purge`` flag. This purge step is a performance optimisation, delete data from the shadow tables in nova database. The behaviour is equal to run juju action ``purge`` on nova-cloud-controller unit, which help to reduce the size of the database, make queries faster, backups efficiency, and follow the data retention policies. The ``purge-before-date`` flag is supported to delete the data older than the date provided. The date string format should be ``YYYY-MM-DD[HH:mm][:ss]``. This flag is useful to retain recent data for debugging or data retention policies. Usage examples -------------- .. terminal:: :input cou plan --purge --purge-before-date 2000-01-02 More information ---------------- - `nova-cloud-controller charm actions`_ - `nova-manage reference`_ - see `purge` subcommand - :doc:`Archive old data ` - :doc:`Nova data migration <../explanation/nova-data-migration>` .. LINKS .. _nova-cloud-controller charm actions: https://charmhub.io/nova-cloud-controller/actions .. _nova-manage reference: https://docs.openstack.org/nova/rocky/cli/nova-manage.html