VMware Cloud Director 10.5.1.1
VMware Encryption Management 1.2
This is caused by adding an high number of entries in the audti_table of Cloud Director database, every time an update call is made from Encryption Management plugin (BYOK).
The issue has been fixed on the Encryption Management plugin 1.2.1 available to download.
To reduce the size of the audit_table you should refer to the article Optimize Cloud Director Performance by reducing the size of the audit_trail table