Hi Ashutosh, Thanks for your information. I do have some questions, but my concern is more on the design doc than branching. Nevertheless, I think it would be very helpful to clarify in the design before we actually put a lot of effort.
>From the design doc, it seems that the cost estimation is based on Tez, while the optimization occurs on logical layer. I'd think that CBO are valuable to either engine. If there is anything that's specific to a particular to an engine, then that optimization should stay at engine layer. My original comments was posted on HIVE-5775. Please let me know your thoughts. I'd also like to hear from the community. https://issues.apache.org/jira/browse/HIVE-5775?focusedCommentId=14039987&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-14039987 Thanks, Xuefu On Thu, Jun 19, 2014 at 10:34 PM, Ashutosh Chauhan <hashut...@apache.org> wrote: > Hi all, > > Some of you may have noticed that cost based optimizer work is going on at > HIVE-5775 John has put up an initial patch there as well. But there is a > lot more work that needs to be done. Following our tradition of large > feature work in branch, I propose that we create a branch and commit this > patch in it and than continue to work on it in branch to improve it. > Hopefully, we can get it in shape so that we can merge it in trunk once its > ready. Unless, I hear otherwise I plan to create a branch and commit this > initial patch by early next week. > > > Design doc is located here : > > https://cwiki.apache.org/confluence/display/Hive/Cost-based+optimization+in+Hive > > > Thanks, > > Ashutosh >
