ACFS Snapshot size growing unreasonably high

Oracle Grid Infrastructure 19.19.0

Hi Community,

we are currently testing ACFS snapshot feature to provide space-efficient copies of Production Database PDB to Test Environment.

This is our setup:

1) CPROD10 CDB with one PDB PROD10 with around 10 TB with is running on production server

2) We are using refreshable PDB to replicate PDB PROD10 to test server with ACFS every hour to a PDB called PDBMASTER. The PDBMASTER is also 10 TB.

3) If we need a fresh copy of the PDB for test environment, then we open the PDBMASTER and then use the command CREATE PLUGGABLE DATABASE PDBTEST1 FROM PDBMASTER SNAPSHOT COPY; This is implicitly creating ACFS snapshots. At this point the snapshot size is very small.