You can drop a table group that contains no table (not being referenced by any table).
Prerequisites
Before you drop a table group, query the DBA_OB_TABLEGROUP_TABLES view to check whether the table group contains tables. You can drop only an empty table group. For more information about how to check whether a table group contains tables by using views, see Query information about a table group.
Drop a table group
The SQL syntax for dropping a table group is as follows:
DROP TABLEGROUP tablegroup_name;
Here, tablegroup_name is the name of the table group to be dropped.
For example, drop the table group tblgroup1.
DROP TABLEGROUP TBLGROUP1;