Hello,

• urlclassifier.sqlite contains the site information for the phishing / malware protection. 
• places.sqlite for example contains your bookmarks and recent history.

However, urlclassifier.sqlite shouldn't be that big. Maybe it could help if you simply delete the file and restart Firefox. It should be recreated on next start.

Cheers,

Tobbi

Splendid! Thanks, Jeroen

I can't find the file by searching my computer. I have Windows 7 Pro version. Does anyone know where this file is stored? I know my file is large because I use Carbonite online backup and it showed urlclassifier3.sqlite as being 184 mb when it backed it up

Un-hide the hidden files and folders.

Not sure about Win7 or Vista, but on W2K & WinXP this is the path to that setting.
Control Panel > Folder Options > View - Advanced Settings

I Upgraded from 3.6.15 to 4.0. This resulted in an increase in size op places.sqlite to 10MB+. Originally it was about 1MB. The biggest problem is not the actual new size, but the fact the profile is stored in my windows profile area. Especially in working environments the windows profile size is limited, as in my case. A 10MB file is a large chunk of a 30MB windows profile.

I see two possible solution: 1. Be able to move your profile outside the windows profile; or 2. Reduce the minimal filesize of places.sqlite

Thanks for the help............

I have the same problem. Just upgraded to 4.0 from 3.x and "places.sqlite" jumped from ~1MB to 10MB. Tried to vacuum it but says the "file is encrypted or is not a database". I am only allowed 30MB for the profile and now if I can't solve this then I will have to either go back to 3.x or uninstall Firefox and stick with IE, which I don't want to do!