Maintaining Thingworx Data Size

Hello,

I've been using the "PurgePropertyHistory" service to delete data from my value streams. The data appears to have been deleted successfully  (when I "QueryPropertyHistory", the resulting infotable returns with no rows).

However, after I run the "PurgePropertyHistory" service, the size of the Postgres database INCREASES significantly. Would someone please explain why the size of the database would increase? I would like to free up space on the database, does anyone have any suggestions? The data is stored on its own drive, separate to any log files.

Thanks