Zoltan Haindrich created CALCITE-6492: -----------------------------------------
Summary: Support aggregate functions which could process DISTINCT natively Key: CALCITE-6492 URL: https://issues.apache.org/jira/browse/CALCITE-6492 Project: Calcite Issue Type: Improvement Reporter: Zoltan Haindrich Assignee: Zoltan Haindrich This could be usefull if the execution engine natively supports some distinct aggregations natively - there is no rewrite necessary for these functions. Currently there is support [SqlAggFunction#getDistinctOptionality|https://github.com/apache/calcite/blob/0deab6f7e0cb4ec63eae8b59477d6f0fadfd11e8/core/src/main/java/org/apache/calcite/sql/SqlAggFunction.java#L187-L189] - which have overlaps with this - possibly the closest would be to set it to *IGNORED* if its supported natively...however * that's a bit misleading as its not IGNORED; but supported... * there is also [checkArgument|https://github.com/apache/calcite/blob/0deab6f7e0cb4ec63eae8b59477d6f0fadfd11e8/core/src/main/java/org/apache/calcite/rel/core/AggregateCall.java#L125] which ensures that *distinct* is not accepted in tht case. More or less the end result would be to also enhance AggregateExpandDistinctAggregatesRule with the ability to ignore aggregates. note: In Druid * if approximationCountDistinct is disabled ; that [enables a calcite rule which rewrites *all* disitnct aggregates|https://github.com/apache/druid/blob/master/sql/src/main/java/org/apache/druid/sql/calcite/planner/CalciteRulesManager.java#L496-L503] * in the meantime there are also some aggregate functions which support *distinct* natively like [string_agg](https://github.com/apache/druid/blob/c9aae9d8e683c0cc9c4687e526b8270f744c57c2/sql/src/main/java/org/apache/druid/sql/calcite/aggregation/builtin/StringSqlAggregator.java#L154) - which doesn't need any rewrites -- This message was sent by Atlassian Jira (v8.20.10#820010)