There is something seriously odd about the
current enwiki backup. The size of one of the two "unexpurgated" backups, theoretically containing all historical page revisions, is actually
smaller than the "current pages only" copy, and the other version (compressed with a different tool) is only a little bigger, despite documentation that one should be about 20x and the other 100x larger.
The last full dump I had a copy of (sadly lost in a disk crash a couple of months ago) was about 70Gb, while the largest now is 5Gb.
I don't have the time or resources right now to bring this copy up to see what is missing (I'm guessing nearly everything, i.e. user and talk page histories), but something seriously screwy is going on here.
(And just to remind of what's above -- this is the
only dump out there. All previous dumps have been erased. Anyone having copies of old dumps, please PM me.)