Julian, thanks for the guides, will log a issue and try to implement it. On Wed, May 10, 2017 at 1:36 AM, Julian Hyde <[email protected]> wrote:
> I don't think it's that hard. We just never got round to it. Can you > log a JIRA case, and submit a pull request when you're done. Be sure > to add a test similar to UdfTest.testUserDefinedAggregateFunction. > > Also, there's no code currently that would call merge, but don't let > that stop you. EnumerableAggregate generates code that calls > EnumerableDefaults.groupBy, which groups all values of the same key > together. We'd use merge if we used a parallel or distributed > algorithm. > > Another piece of code that could call merge is roll-up: see > SubstitutionVisitor.getRollup. > > Julian > > > On Tue, May 9, 2017 at 8:03 AM, James <[email protected]> wrote: > > I was implementing UDAF based on calcite, but found that merge method is > > not implemented: > > > > https://github.com/apache/calcite/blob/0938c7b6d767e3242874d87a30d911 > 2512d9243a/core/src/main/java/org/apache/calcite/schema/ > impl/AggregateFunctionImpl.java#L86 > > > > I just wonder why it is not implemented? As a newbie to calcite, it seems > > not so hard to implement the merge. Are there any issue blocking the > > implemention of merge, or just a matter of time? If it is just a matter > of > > time, I'd like to spend some time implementing it. > > > > Thanks in advance. > > James >
