What is pzpvstream in pega?

Pega uses a concept called Storage Stream (aka. The full PRPC object image is stored in the database table within the pzPVStream column, defined as a BLOB datatype. Values of properties with a mode other than Single Value (such as mode Page or Page List ) are stored in a special column named pzPVStream. When I researched a bit about this, I got to know the contents of the column are compressed befored stored into database. Pega database supports blob storage.