In the Oracle database there are lots of KEYSET tables. These tables are used by ArcGIS and basically dropped terminating a session. When accessing the database with UT for ArcGIS, these tables are not dropped.
Why these tables are not dropped accessing the database from UT for ArcGIS is unknown so far. Negative effects on application behavior could not be determined, also with lots of orphaned KEYSET tables.
KEYSET tables are also not dropped, if the session terminates abnormally. For this reason Esri provides a procedure, which allows dropping orphaned KEYSET tables. To cleanup this procedure can be executed regularly.