Whenever you open or close a window SQL Visualizer retains enough information for you to be able to re-open the window using the same criteria. For example if you close a query you can go to the Recently used windows list and re-open the query even is it was never saved.

This same principal applies to all windows, such as data visualizers and the help contents.

This allows you to back track through previous actions without requiring all windows to constantly remain open.

N.B. The recently used window list is not persisted between sessions, once the application is closed the list is cleared.