Click the Sort toolbar button. If you want to define a multi-field sort key, press and hold down the Shift key.

To specify more complex sort keys and to change the default comparison functions, use the Tools > Sort command.

When sorting Long Text, Images/Files and Code fields, GS-Base compares the total size of the field contents.
Note: Objects inserted as links (shortcuts) to external files (with the Insert Shortcut to... command) will be sorted by size if they were inserted in GS-Base ver. 12.1.3 or later. Unless re-inserted, earlier links will be treated as 1-byte objects.