the grass on the other side of the hill

From http://slashdot.org/article.pl?sid=06/11/09/1534204

"Last night we crossed over 16,777,216 comments in the database. The
wise amongst you might note that this number is 2^24, or in MySQLese an
unsigned mediumint. Unfortunately, like 5 years ago we changed our
primary keys in the comment table to unsigned int (32 bits, or 4.1
billion) but neglected to change the index that handles parents. We're
awesome! Fixing is a simple ALTER TABLE statement... but on a table that
is 16 million rows long, our system will take 3+ hours to do it, during
which time there can be no posting. So today, we're disabling threading
and will enable it again later tonight. Sorry for the inconvenience. We
shall flog ourselves appropriately."

Hilarious!

Vassilis.