In this directory, you can organize the registered database instances by creating files in a tree structure. To move files to different levels within a directory, select the required file and, keeping the left-hand mouse button pressed down, drag it to the desired location .
If you select a directory, the database instances registered in it and all subdirectories are displayed in the
list of registered database instances. The file at the highest level (Databases) contains all the registered database instances.You can display or hide this tree structure. To do this, choose View ® Tree and select or deselect Tree.
The
area on the screen shown in red below is the directory of registered database instances.