A friend sent this to me today. Firefox uses a bunch of .sqlite files to manage it’s persistent data like your preferences in the “awesomebar”. These files can get quite big and cause a slow computer when using firefox; especially when using the awesomebar and closing the application.

OS X users can use this command to “compact” these files:

for f in ~/.mozilla/firefox/*/*.sqlite; do sqlite3 $f 'VACUUM;'; done

Windows users can make use of the SQLite addon to do the same thing. Install the addon, then go to %appdata%mozillafirefoxprofilesxxxxx and look for the .sqlite files.