alamb commented on code in PR #18441: URL: https://github.com/apache/datafusion/pull/18441#discussion_r2515015669
########## docs/source/library-user-guide/upgrading.md: ########## @@ -261,6 +261,23 @@ The accompanying `AggregateUDF::is_ordered_set_aggregate` has also been renamed No functionality has been changed with regards to this method; it still refers only to permitting use of `WITHIN GROUP` SQL syntax for the aggregate function. +### `AggregateUDFImpl::supports_null_handling_clause` now defaults to `false` Review Comment: when we merge we should move this section to the section for datafusion 52 ########## docs/source/library-user-guide/upgrading.md: ########## @@ -261,6 +261,23 @@ The accompanying `AggregateUDF::is_ordered_set_aggregate` has also been renamed No functionality has been changed with regards to this method; it still refers only to permitting use of `WITHIN GROUP` SQL syntax for the aggregate function. +### `AggregateUDFImpl::supports_null_handling_clause` now defaults to `false` + +This method specifies whether an aggregate function allows `IGNORE NULLS`/`RESPECT NULLS` +during SQL parsing, with the implication it respects these configs during computation. +For the vast majority of DataFusion aggregate functions, they do not actually make +use of this config even though by default it is permitted. We change this so only +the few functions which do respect this clause (e.g. `array_agg`, `first_value`, +`last_value`) need to implement it. Review Comment: Here is a suggestion to make the implications clearer: ```suggestion Most DataFusion aggregate functions, silently ignored this config and syntax in prior versions. We change this so only the few functions which do respect this clause such as `array_agg`, `first_value`, and `last_value` implement it. User defined aggregate functions will also error if this syntax is used, unless they explicitly declare support via `AggregateUDFImpl::supports_null_handling_clause` ``` -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
