When running some queries using F5, Toad hangs or takes a long time before it return results. This is only a problem when running with F5 Execute Script.
Using F9 or in SQL Plus does not have the same problem. This is also only a problem with some queries.Very short queries that return only a few records will come up quickly. The more records, the slower the results and sometimes it hangs.
select * from V$SESSION;
-- If this returns 10 rows, it takes about 40 seconds to return results if run with F5. It returns in msec if run by other means.
-- If this returns more rows, it can take minutes to return.
Toads Editor window has the options to Maintain Script History. This slows down Toads run with F5 Execute Script. This option does not affect F9 Executes as Statement or SQL Plus.
Go to View | Options | Execute/Compile and uncheck/disable Maintain Script History option.