Data recovery after inadvertent update?

Hi all

Someone on SO has UPDATEd away some data they cared about. I've written
a bit on what they might want to do, but really don't know enough, so I
was hoping for some aid/ideas. In particular, is the advice to use "
pg_ctl stop -m immediate" (to hopefully avoid a checkpoint) appropriate
and useful? I'm just not sure.

http://stackoverflow.com/questions/12472318/can-i-rollback-a-transaction-ive-already-committed-data-loss

Also, are there any functions to read raw tuple bytes to `RECORD's? I
couldn't find any in `pageinspect', `pgstattuple', `adminpack', etc. Am
I right in guessing that they're pretty much going to require hand data
recovery or the use of some custom C extension code to get at the data -
if it still exists?

--
Craig Ringer