But What happened the this tablespace was getting full, increase it 20GB is not enough which mean it’s strange case and not acceptable.
after investigation Table Called “REFERENCE_INSTANCE” include information about Running Composite in SOA ans instances. the size for this table 18GB.
Select * from Reference_instance;
Check the data in the above query, just in case you can use export data-bump utility for this table, however after this Truncate the table and from full tablespace toonly 2% usage.