PITR - recovery to a particular transaction

The PITR docs that have just been put up say:

But if you want to recover to some previous point in time (say,
right before the junior DBA dropped your main transaction
table), just specify the required stopping point in
recovery.conf. You can specify the stop point either by
date/time or by transaction ID. As of this writing only the
date/time option is very usable, since there are no tools to
help you identify which transaction ID to use.

How about adding a logging option to put the transaction id on the log
for every statement that modifies the database? Would that be a small
enough change to be allowed into 8.0?
--
Oliver Elphick olly(at)lfix(dot)co(dot)uk
Isle of Wight http://www.lfix.co.uk/oliver
GPG: 1024D/A54310EA 92C8 39E7 280E 3631 3F0E 1EC0 5664 7A2F A543 10EA
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"And not only so, but we glory in tribulations also;
knowing that tribulation worketh patience; And
patience, experience; and experience, hope."
Romans 5:3,4