In many cases, people want to drop a range of keys. For example, in MyRocks, we encoded rows from one table by prefixing with table ID, so that when we need to drop a table, all keys with the prefix needs to be dropped. For another example, if we store different attributes of a user with key with the format , then if a user deletes the account, we need to delete all the keys prefixing [user_id].

There are two other ways you can do to delete keys from a range:

Another way is to apply compaction filter together with CompactRange(). You can write a compaction filter that can filter out keys from deleted range. When you want to delete keys from a range, call for the range to delete. While the compaction finishes, the keys will be dropped. We recommend you to turn CompactionFilter::IgnoreSnapshots() to true to make sure keys are dropped even if you have outstanding snapshots. Otherwise, you may not be able to fully remove all the keys in the range from the system. This approach can also solve the problem of reclaiming data, but it introduces more I/Os than the DeleteFilesInRange() approach. However, DeleteFilesInRange() cannot remove all the data in the range. So a better way is to first apply DeleteFilesInRange(), and then issue CompactRange() with compaction filter.