I'd like to be part of it, for anything it takes, discussion, review, code contribution, whatever.
Thanks, Maryann On Sun, Dec 13, 2015 at 8:13 PM, Julian Hyde <[email protected]> wrote: > tl;dr: Please can at least one person from Drill, Hive, Phoenix, and > any other interested stakeholders, review and join the discussion in > https://issues.apache.org/jira/browse/CALCITE-794. > > --- > > We currently have to treat carefully when evaluating metadata (e.g. > row count, whether columns are keys) because RelNode graphs are > allowed to be cyclic. This occurs when you are using the Volcano > planner and it is easy for a sequence of merges to cause subsets to be > ancestors of themselves. > > My proposed solution is to require a call context when asking for > metadata. RelMetadataQuery, previously abstract, becomes that context. > It maintains a map of all active metadata calls, and can therefore > detect cycles. > > The issue is https://issues.apache.org/jira/browse/CALCITE-794 and > attached to it is a development branch that is ready for review. (The > test suite passes, but a few important tests are disabled, so it's not > ready to commit just yet.) > > Please review. > > This is an important change, and changes some key APIs, so I would > like a +1 from Calcite stakeholders, including from a least one > committer from each of the Drill, Hive, Phoenix projects, before I > proceed. > > I'd like to discuss (a) whether this is the right change, (b) whether > this should go in the 1.6 release (some time this month), (c) whether > this justifies upping Calcite's version to 2.0. > > In my opinion, this can go into 1.6 this month, if we can get the > disabled tests to pass and we prove that performance is at par. > > Julian >
