About a year ago, I told you about how to vacuum Firefox’s SQLite database to make it run better.
The trick still works, but they moved stuff around on us in Firefox 7.
Now what you have to do is go to Tools, Web Developer, Error Console (or just hit ctrl-shift-j) and paste in the following long line:
Components.classes["@mozilla.org/browser/nav-history-service;1"].getService(Components.interfaces.nsPIPlacesDatabase).DBConnection.executeSimpleSQL("VACUUM");
The line ends in a semicolon, so make sure you get the line in its entirety. The easiest way to do that is to triple-click on the line. Thanks to Bill James for reminding me of that.
After pasting in the line, click evaluate. Firefox will appear to freeze, but behind the scenes, it’s working overtime. Wait for Firefox to recover, and it’ll run a lot better afterward with all that slack space dumped from the database. How often you’ll want to do this depends on how heavily you use Firefox, but I find I need to do it every 6-12 months.

David Farquhar is a computer security professional, entrepreneur, and author. He has written professionally about computers since 1991, so he was writing about retro computers when they were still new. He has been working in IT professionally since 1994 and has specialized in vulnerability management since 2013. He holds Security+ and CISSP certifications. Today he blogs five times a week, mostly about retro computers and retro gaming covering the time period from 1975 to 2000.

Just triple click on the line.
I’d completely forgotten that trick. Thanks. I’ll update the post accordingly.