+1, I think it's good for both end-users and Spark developers: * for end-users, when they lookup a table, they don't need to care which command triggers it, as the behavior is consistent in all the places. * for Spark developers, we may simplify the code quite a bit. For now we have two code paths to lookup tables: one for SELECT/INSERT and one for other commands.
Thanks, Wenchen On Mon, Dec 2, 2019 at 9:12 AM Terry Kim <yumin...@gmail.com> wrote: > Hi all, > > As discussed in SPARK-29900, Spark currently has two different relation > resolution behaviors: > > 1. Look up temp view first, then table/persistent view > 2. Look up table/persistent view > > The first behavior is used in SELECT, INSERT and a few commands that > support temp views such as DESCRIBE TABLE, etc. The second behavior is used > in most commands. Thus, it is hard to predict which relation resolution > rule is being applied for a given command. > > I want to propose a consistent relation resolution behavior in which temp > views are always looked up first before table/persistent view, as > described more in detail in this doc: consistent relation resolution > proposal > <https://docs.google.com/document/d/1hvLjGA8y_W_hhilpngXVub1Ebv8RsMap986nENCFnrg/edit?usp=sharing> > . > > Note that this proposal is a breaking change, but the impact should be > minimal since this applies only when there are temp views and tables with > the same name. > > Any feedback will be appreciated. > > I also want to thank Wenchen Fan, Ryan Blue, Burak Yavuz, and Dongjoon > Hyun for guidance and suggestion. > > Regards, > Terry > > > <https://issues.apache.org/jira/browse/SPARK-29900> >
