In the data grid, it seems the previous data set causes the subsequent query to retain its previous column width.
The following two queries below demonstrates the problem.
In the Editor, run the following two queries one after another:
Select sysdate as "xx" from dual where 0 = 1;
Select sysdate as "xx" from dual;
On the first query, the grid is sized appropriately, since nothing is returned it is very narrow.
Running the second query should automatically resize the column for the date; however it retains the previous column size.
One needs to manually resize the width to see the date.
Waiting for fix in a future version of Toad for Oracle.