It was 3am in the morning and I was asleep and enjoying a delightful dream (I knew it was a dream because I was surrounded by drifting clouds, singing angels and hundreds of softly humming SQL Servers where the hardware had been sensibly provisioned and all code carefully optimised) when I was rudely awoken by a Service Desk call informing me that the systems were unresponsive. A quick check and I could see that everything was being blocked a particular transaction. My suspicion was that someone had run a script which had opened a transaction and then toddled off home without checking that either the script had finished or closed the transaction that it had opened.
My guess was right and killing the transaction got the cogs turning again.
Click through for the script.