These are cache files. It basically takes websites that you access a lot and saves bits of them so they'll load faster the next time you visit them. E.G. If you visit Google.com a lot, Firefox will save some elements of that page in the cache so the next time you visit Google.com, it won't have to re-download them.

I wouldn't recommend permanently disabling the cache, but you can delete these files when you want by clearing the cache. If you want to automatically clear the cache, click here.

If you want to limit how much space Firefox can use for the cache, click the menu button, Options button, click the Advanced tab, click the Network sub-tab, check Override Automatic Cache Management, and select how much space you want to give to Firefox for caching. If you set this to 300 MB, Firefox will be able to store up to 300 MB of cache on your computer, but can't go over 300 MB resulting in the oldest files being deleted to make way for new files.

I have original poster beat. I just had NO CHOICE but to delete ALL entries in the cache2 folder because there was almost 90,000 entries taking 1.4 GIG. And YES, I triede all normal ideas short of turning cache off including the various automatically cleaning and all that, I even had CCleaner scan Firefox and those file NEVER showed as cache. So, now I have NO choice but to see what happens after I completely disable the cache. I mean having it accumulate that much data and NO way to clean up after itself is ludicrous. This needs fixed properly in next release or 2 (I have v39).

Besides, 1.) I had the cache set in the FF config for ONLY 128 MEG, NOTHING IN THE gig RANGE. AND 2.) the cache clean after shutdown acted like it could not even see that stuff. So, like I stated, NO CHOICE but to manually delete the entire contents.

CyberWolf64,

Please start your own thread here - https://support.mozilla.org/en-US/questions/new

It is possible that using external software like CCleaner has caused such an issue in the first place or the cache management files got broken otherwise (crashes) although Firefox should detect the latter due the presence of a dirty cache flag, so always use such external cleaners with care.

If all files do not show on the about:cache page then best is to clear the entire cache2 location as shown on the about:cache page.

After some testing, I do actually be;lieve that somehow CCleaner may have "broken" the database files both in Firefox and Thunderbird. So, no longer allowing it to "clean" those 2 programs.

places.sqlite is not a simple database file, but has a lot of tables that are all linked to each other via specific fields. Because of that the database gets easily corrupted if you allow other software to make changes to this file.