Symantec Data Loss Prevention (DLP)
We require DLP's LOB_tablespace to be in SecureFile (see Converting your LOB tables from BasicFiles to SecureFiles format) for all DLP versions after 15.5.
One of the features explained was better reclamation of the space.
This creates confusion since the Symantec Reclamation tool was previously used to reclaim space in the database.
Oracle's Automatic Segment Space Management (ASSM) is designed for efficiency in the database, meant for reuse and speed.
Oracle space management is not designed to redo the size of the files once it has been allocated.
Deleting incidents allows SecureFile to reuse the space in more efficient manner, it does not empty the space.
Since it does not empty the space, it will not show files shrinking.
SecureFile provides performance improvements to our LOB storage by utilizing Oracle's Automatic Space Management (ASSM).
SecureFile tracks deleted LOBs and makes that space available for Oracle to reuse after the retention period expires.
After converting to SecureFile LOB storage, you do not need to run a script to "reclaim" LOB space in your database.
SecureFile will now re-purpose that space for Oracle to use automatically in a way where that space is no longer unusable like it could potentially be with BasicFile.
If SecureFile spent the time required to resize the files, that is time it wastes not able to process requests.