The index on Block.Size improves the performance of the query that
checks that the user has not altered the block size of the backup
configuration.
The index on Block.Hash and Block.VolumeID improves the performance of
the query that obtains the blocklists.
There are anecdotes that these indices can drastically improve
performance (queries that used to take hours completed in seconds with
the index):
https://forum.duplicati.com/t/repairing-a-big-database/8174/4https://github.com/duplicati/duplicati/issues/3884#issuecomment-612296016
This fixes issue #3884.
