What is the schema of the data stores used by the reference client?
There are the bitcoin-tools by Gavin Andresen but they will only work up to version 0.7 of Bitcoin-QT. If your goal is to simply check whether the blocks are version 1 or 2 I suggest you do something like this:

MAX_HEIGHT=`bitcoind getinfo | grep blocks | grep -oE '[0-9]+'`
MIN_HEIGHT=210000
for HEIGHT in `seq $MAX_HEIGHT -1 $MIN_HEIGHT`; do
  HASH=`bitcoind getblockhash $HEIGHT`
  VERSION=`bitcoind getblock $HASH | grep version | grep -oE '[0-9]+'`
  echo $HEIGHT,$HASH,$VERSION
done &gt;&gt; block-versions.csv


This will get you a Comma-Separated file with the block's height,its hash and version.