Data Scrubbing¶

While data encryption ensures that the existing data are not stored in plain form, the data scrubbing literally removes the data once the user decides they should be deleted. Compare this behavior with how the DELETE statement works which only marks the affected data as deleted - the space claimed by this data is overwritten with new data later.

Once enabled, data scrubbing works automatically on each tablespace separately. To enable data scrubbing, you need to set the following variables:

• innodb-background-scrub-data-uncompressed
• innodb-background-scrub-data-compressed

Uncompressed tables can also be scrubbed immediately, independently of key rotation or background threads. This can be enabled by setting the variable innodb-immediate-scrub-data-uncompressed. This option is not supported for compressed tables.

Note that data scrubbing is made effective by setting the innodb_online_encryption_threads variable to a value greater than zero.