When using PL/SQL Developer (Allround Automations), a internal query is taking a lot of cpu cycles on database server (100% of a CPU).
Is this your problem? Please check if the query is like this:
select s.synonym_name object_name, o.object_type
from sys.all_synonyms s,
sys.all_objects o
where s.owner in ('PUBLIC', user)
and o.owner = s.table_owner
and o.object_name = s.table_name
and o.object_type in ('TABLE', 'VIEW', 'PACKAGE','TYPE', 'PROCEDURE', 'FUNCTION', 'SEQUENCE')
It’s caused by the Describe Context Option of Code Assistant. To disable it:
Tools > Preferences > Code Assistant and disable the “Describe Context” option.