Aaron Halfaker, 10/05/2012 23:34:
As you can see in the conversation below, I discovered that sha1 hashes are not being generated historically for revision content in Wikipedia -- just generated from the time of release (mid-April) forward. Is this intended? If so, is there a plan to fill in the sha1's historically or should we (data monkeys) keep track of THE GREAT SHA1 EPOCH of April, 2012 when performing our analysis from here forward?
There's nothing strange in this behaviour, it's been always like that for similar new columns, they need to be populated (usually, they are after a few years). Bug: https://bugzilla.wikimedia.org/show_bug.cgi?id=36081
Nemo