UPDATE I removed tracker, when I rebooted my machine again my memory cache got ~1000M again, and again, and again.
I didn't knew it existed until recently, that I saw all my memory was eaten up and suddenly I was using my SWAP instead of my memory, and it was fully loaded.
What's my surprise? I have 2G in memory and 1113M of it was cache, and 1G of swap full as well. The worst thing is that I reboot my machine and without starting anything I get 903M of cache full, out of nowhere!
I start to track what's the issue, where's the leak, and found that if I killed tracker-store early then my memory stopped being loaded of cache.
There's a bug, already reported, it's #612242 and the workaround given is to nuke the database with
It worked. Now my cache is not full, but since I just did it I don't know if in some days my tracker-cache will be full again and eating all my memory.
Just wanted people know there was a work-around at least and you could use your computer again.