I think that basically the disk format change was too far a bridge to cross. You can't tell customers that they should quadruple their cluster so that they can

I think that basically the disk format change was too far a bridge to cross. You can't tell customers that they should quadruple their cluster so that they can dump their data and reimport it to perform the upgrade. The planner is basically entirely different. It was later extracted into a standalone module to build HAWQ[0]. Since then there has been work to build a new shared query planner called GPORCA[1]. [0] https://hawq.apache.org/ https://hawq.apache.org/ [1] http://engineering.pivotal.io/post/gporca-open-source/ http://engineering.pivotal.io/post/gporca-open-source/