[jira] [Created] (CALCITE-1489) Add rule, AggegateValuesRule, that applies to Aggregate on empty relation

["Julian Hyde (JIRA)" <ji...@apache.org>]

Julian Hyde created CALCITE-1489:
------------------------------------

             Summary: Add rule, AggegateValuesRule, that applies to Aggregate on empty relation
                 Key: CALCITE-1489
                 URL: https://issues.apache.org/jira/browse/CALCITE-1489
             Project: Calcite
          Issue Type: Bug
            Reporter: Julian Hyde
            Assignee: Julian Hyde


Let's call it {{AggregateValuesRule}}, consistent with the naming convention where we start with the type of rel(s) being acted on. Initially it would apply to an empty {{Values}}, but potentially it could apply to one or more values.

I don't recall aggregates having a way to tell us what they will return on empty (or constant) input. In future we could use the constant reducer for that, but for now, the rule should match a particular set of aggregates: {{COUNT}} and {{SUM0}} return zero; {{MIN}}, {{MAX}}, {{SUM}} return null. It must abort if it sees an aggregate it does not know how to handle.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)