The HBase book ( http://hbase.apache.org/book/upgrading.html ) states,
> This version of 0.90.x HBase can be started on data written by HBase 0.20.x or HBase 0.89.x. There is no
> need of a migration step. HBase 0.89.x and 0.90.x does write out the name of region directories differently --
> it names them with a md5 hash of the region name rather than a jenkins hash -- so this means that once
> started, there is no going back to HBase 0.20.x.
Does this mean that if we prevent region splits, that it would be
possible to rollback to HBase 0.20.6, or are there other data format
changes that would prevent that?