Comment 71 for bug 215728

There may be a few different problems here. First problem may be sqlite vacuums. It looks to me like Firefox occasionally reads and writes the entire contents of large sqlite files (~50MB in my profile). Second, there seems to be very excessive preallocation or wasting of space. For example I just did an offline sqlite vacuum which reduced my profile from 50MB to 38MB. Then I started the browser and visited one site, and the sqlite files in my profile are up to 47MB. That's 9MB for one site visit?

The reason I suspect a vacuum issue is that I see this very regularly. Just as a rough guess, I get a 20-30 second hang on every 20 page loads.

I'm testing with Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9b5) Gecko/2008041514 Firefox/3.0b5