Oracle VSS writer supports log, copy, full, differential, and incremental backups.

The VSS writer uses time stamp mechanism for incremental and differential backups and stores a time stamp in the backup document using SetBackupStamp() API. This backup stamp is used by Oracle VSS writer during incremental or differential backups to specify changed files since the last full or incremental backup using AddDifferencedFilesByLastModifyTime() API.

Oracle VSS writer also stores backup metadata and restore metadata, which must be available during restore operations so that the VSS writer can perform intelligent postrestore operations. In case of full or copy backup, the restore metadata contains important redo information to make the restored files consistent. Hence, it is imperative that Oracle VSS writer is called during restore operations to perform the recovery operations.