I'm running SQL Developer 18.2 on Windows 10 v1803.
In Windows, I've associated the file type extension .sql with the SQL Developer application (and other source code file types as well).
Now when I double-click the filename.sql , SQL Developer opens, which is what we'd expect.
Here's the problem. If I've got a running instance of SQL Developer and I open Windows file Explorer to browse and intentionally or unintentionally "Open" on a .sql file (or any file type associated with SQL developer) by selecting it and pressing enter or double clicking on it; a second instance of SQL Developer launches. I only want and need a single instance of SQL Developer running at any given time.
In Windows, if you multi-select several (let's say 5) files and press enter, the associated application is opened five (5) times. A unpleasant time and RAM consuming user experience.
Suggestion:
It would be great if possible if a new Singleton "setting" was added which when enabled, would detect whether there is an existing running instance and if so, terminate immediately. That describes the Singleton pattern.
The benefit is that for those with limited amount of RAM e.g. 4GB can retain enable this setting, and those with Hugh amounts of RAM can disable this new setting and have as many running instances as they desire.