You won't need to use this menu option very often, if ever; and I'm not going to spend a lot of time explaining it. Putting it as simply as I can, databases that are constantly being written to, and deleted from, and on the end of lots of updates, can get 'flabby' over time. Internal space that was used to store a piece of data that gets deleted may never get re-used, meaning it's taking up space and doing nothing to earn its keep. Over time, that wasted space means the database has to process 'blanks' rather than real data. That can slow things down.
Database developers are aware of this, however, and therefore provide 'vaccuming' options which tidy up all the dead space, compacting things back to maximum efficiency, and rebuilding indexes to make them as small (and hence as fast) as possible, too.
This inherent database functionality is what Giocoso's Database Management menu Option 7 triggers.
Taking this option triggers the appearance of the standard 'select a database' form. Once a database has been selected and the [Enter] key pressed, the relevant internal database maintenance commands are given and a confirmation message that the database has been 'compacted and optimised' will be displayed. And that's really all there is to this option!
There are a couple of caveats to mention, however. The first and most significant is: don't take this menu option if music is actually being played by another Giocoso session elsewhere. The optimisation process is 'blocking': that is, it will prevent the music-playing session from reading or writing from the database. The second point is: don't use this option very often. Compacting a database is a 'good' thing, like chocolate. But, also like chocolate, too much of a good thing is a bad thing: constantly compacting a database risks corrupting it, and you definitely don't want that happening!
The only reason for ever using this menu option is if you have an enormous music database and are constantly deleting from it, adding to it, and updating what's inside it. Even then, those sorts of operations should not cause noticeable 'bloat' in the database -so, you'd only even consider taking this optimisation option if you noticed real and significant degredation in, say, the length of time it takes Giocoso to find a piece of music to play at random, or if a report that used to be created in sub-second time starts to take multiple tens of seconds to complete. Short of that sort of obvious deterioration in performance, you are best to leave this menu option entirely alone.