Make Firefox faster by vacuuming its databases (took me 10 seconds) (UPDATE)

2 ways to do it:

1. Install the VacuumPlaces extension or

2. Follow these instructions:

• Open the Error Console: Tools menu/Error Console
• In the Code text box paste this (it’s a single line):

  Components.classes["@mozilla.org/browser/nav-history-service;1"].getService(Components.interfaces.nsPIPlacesDatabase).DBConnection.executeSimpleSQL("VACUUM");

• Press Evaluate. All the UI will freeze for a few seconds while databases are VACUUMed

from mozillalinks, hat-tip lifehacker.

UPDATE: The VacuumPlaces extension has been improved. hat-tip lifehacker.