Check this post on depesz.com:
http://www.depesz.com/2012/04/04/lets-talk-dirty/
2012/9/18 Craig Ringer <ringerc(at)ringerc(dot)id(dot)au>
> 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?
>
--
Victor Y. Yegorov