TABLES_SNAP_TIMESTAMP records the start and end time of the snapshots created for each performance view. After enable_wdr_snapshot is set to on, this catalog is created and maintained by the background snapshot thread. It is accessible only to users with system administrator rights.

**Table 1** dbms_om.tables_snap_timestamp columns
Name	Type	Description
snapshot_id	name	Snapshot ID. This column is the primary key and distribution key.
db_name	text	Name of the database to which the view belongs
tablename	text	View name
start_ts	timestamp with time zone	Snapshot start time
end_ts	timestamp with time zone	Snapshot end time

This system catalog's schema is dbms_om.
Do not modify or delete this catalog externally. Otherwise, functions related to view snapshots may not work properly.