try to expand Public Synonyms on any database connection and it hangs indefinitely. It appears to be running this sql:
select t.*, substr(concat,1,instr(concat,'/')-1) TABLE_TYPE, substr(concat,instr(concat,'/')+1, length(concat)-instr(concat,'/')) TABLE_ID
select s.synonym_name, s.table_owner, s.table_name, o1.object_id, o1.object_type || '/' || object_id concat
from all_synonyms s, sys.all_objects o1
where s.owner = 'PUBLIC' and s.owner = o1.owner(+) and o1.object_type(+) = 'SYNONYM' and s.synonym_name = o1.object_name(+) ) t )
But that sql runs in a second or so when pasted into a window.
Target database is 220.127.116.11.0 running on OEL.
Anyone else noticed the same problem?
I suppose it's possible there is some special issue with 18.104.22.168 and you've encountered something new; however, this is typically a performance issue rather than a hang. See the following thread: 3.1 - Public Synonyms - Hanging
I would add that the cancellation issue has been fixed, but that the window of opportunity is very brief -- just a few seconds at most -- since cancellation only applies to the SQL query. As you note, that is very fast. Once SQL Developer has the result of the query, it begins to render all those individual nodes in the navigator tree. That is what really takes so long and, unfortunately, cannot be cancelled. Use the filter trick mentioned in the other thread to protect yourself from such 'accidental' delays.
SQL Developer Team