RelMdDistribution (the "Md" that distinguishes it from "RelDistribution" stands for "metadata") is just theory, but it will look a lot like RelMdCollation.
https://github.com/apache/incubator-calcite/blob/master/core/src/main/java/org/apache/calcite/rel/metadata/RelMdCollation.java On Wed, Feb 11, 2015 at 6:47 PM, Ashutosh Chauhan <[email protected]> wrote: > I think RelDistribution as a member of Exchange (as in Julian proposal) > makes more sense as compared to mine at field level. > > On Wed, Feb 11, 2015 at 6:42 PM, Jacques Nadeau <[email protected]> wrote: > >> Does RelMdDistribution exist or as theory? >> >> Definitely inclined to "Exchange" over "Shuffle" as more generic/consistent >> with Volcano. >> >> Note, looking at Ashutosh I wonder a little about the need to have range >> versus hash at the field information level. I'm sure we can come up with a >> use case but it seems to overcomplicate. We already have space exploration >> problems when trying to do distribution subsumption for joins with trait >> propagation so I would be cautious about adding more dimensions to that >> attribute. >>
