alamb commented on code in PR #17255: URL: https://github.com/apache/datafusion/pull/17255#discussion_r2294598360
########## datafusion/sqllogictest/test_files/aggregate.slt: ########## @@ -7387,3 +7389,58 @@ FROM (VALUES ('a'), ('d'), ('c'), ('a')) t(a_varchar); query error Error during planning: ORDER BY and WITHIN GROUP clauses cannot be used together in the same aggregate function SELECT array_agg(a_varchar order by a_varchar) WITHIN GROUP (ORDER BY a_varchar) FROM (VALUES ('a'), ('d'), ('c'), ('a')) t(a_varchar); + +# distinct average +statement ok +create table distinct_avg (a int, b int) as values + (null, null), + (1, 1), + (2, 2), + (3, 3), + (4, 4), Review Comment: Could you update this test so: 1. The input isn't in order 2. Add a test for floating point values 3. Test for an input that includes at least one null value 4. the values in `b` are different than the values in `b` ########## datafusion/functions-aggregate/src/average.rs: ########## @@ -114,79 +115,95 @@ impl AggregateUDFImpl for Avg { } fn accumulator(&self, acc_args: AccumulatorArgs) -> Result<Box<dyn Accumulator>> { - if acc_args.is_distinct { - return exec_err!("avg(DISTINCT) aggregations are not available"); - } + let data_type = acc_args.exprs[0].data_type(acc_args.schema)?; use DataType::*; - let data_type = acc_args.exprs[0].data_type(acc_args.schema)?; // instantiate specialized accumulator based for the type - match (&data_type, acc_args.return_field.data_type()) { - (Float64, Float64) => Ok(Box::<AvgAccumulator>::default()), - ( - Decimal128(sum_precision, sum_scale), - Decimal128(target_precision, target_scale), - ) => Ok(Box::new(DecimalAvgAccumulator::<Decimal128Type> { - sum: None, - count: 0, - sum_scale: *sum_scale, - sum_precision: *sum_precision, - target_precision: *target_precision, - target_scale: *target_scale, - })), - - ( - Decimal256(sum_precision, sum_scale), - Decimal256(target_precision, target_scale), - ) => Ok(Box::new(DecimalAvgAccumulator::<Decimal256Type> { - sum: None, - count: 0, - sum_scale: *sum_scale, - sum_precision: *sum_precision, - target_precision: *target_precision, - target_scale: *target_scale, - })), - - (Duration(time_unit), Duration(result_unit)) => { - Ok(Box::new(DurationAvgAccumulator { + if acc_args.is_distinct { + match &data_type { + // Numeric types are converted to Float64 via `coerce_avg_type` during logical plan creation + Float64 => Ok(Box::new(Float64DistinctAvgAccumulator::default())), + _ => exec_err!("AVG(DISTINCT) for {} not supported", data_type), + } + } else { + match (&data_type, acc_args.return_field.data_type()) { + (Float64, Float64) => Ok(Box::<AvgAccumulator>::default()), + ( + Decimal128(sum_precision, sum_scale), + Decimal128(target_precision, target_scale), + ) => Ok(Box::new(DecimalAvgAccumulator::<Decimal128Type> { sum: None, count: 0, - time_unit: *time_unit, - result_unit: *result_unit, - })) - } + sum_scale: *sum_scale, + sum_precision: *sum_precision, + target_precision: *target_precision, + target_scale: *target_scale, + })), + + ( + Decimal256(sum_precision, sum_scale), + Decimal256(target_precision, target_scale), + ) => Ok(Box::new(DecimalAvgAccumulator::<Decimal256Type> { + sum: None, + count: 0, + sum_scale: *sum_scale, + sum_precision: *sum_precision, + target_precision: *target_precision, + target_scale: *target_scale, + })), + + (Duration(time_unit), Duration(result_unit)) => { + Ok(Box::new(DurationAvgAccumulator { + sum: None, + count: 0, + time_unit: *time_unit, + result_unit: *result_unit, + })) + } - _ => exec_err!( - "AvgAccumulator for ({} --> {})", - &data_type, - acc_args.return_field.data_type() - ), + _ => exec_err!( + "AvgAccumulator for ({} --> {})", + &data_type, + acc_args.return_field.data_type() + ), + } } } fn state_fields(&self, args: StateFieldsArgs) -> Result<Vec<FieldRef>> { - Ok(vec![ - Field::new( - format_state_name(args.name, "count"), - DataType::UInt64, - true, - ), - Field::new( - format_state_name(args.name, "sum"), - args.input_fields[0].data_type().clone(), - true, - ), - ] - .into_iter() - .map(Arc::new) - .collect()) + if args.is_distinct { + // Copied from datafusion_functions_aggregate::sum::Sum::state_fields + // since the accumulator uses DistinctSumAccumulator internally. + Ok(vec![Field::new_list( + format_state_name(args.name, "sum distinct"), Review Comment: ```suggestion format_state_name(args.name, "avg distinct"), ``` ########## datafusion/functions-aggregate/src/average.rs: ########## @@ -114,72 +115,88 @@ impl AggregateUDFImpl for Avg { } fn accumulator(&self, acc_args: AccumulatorArgs) -> Result<Box<dyn Accumulator>> { - if acc_args.is_distinct { - return exec_err!("avg(DISTINCT) aggregations are not available"); - } + let data_type = acc_args.exprs[0].data_type(acc_args.schema)?; use DataType::*; - let data_type = acc_args.exprs[0].data_type(acc_args.schema)?; // instantiate specialized accumulator based for the type - match (&data_type, acc_args.return_field.data_type()) { - (Float64, Float64) => Ok(Box::<AvgAccumulator>::default()), - ( - Decimal128(sum_precision, sum_scale), - Decimal128(target_precision, target_scale), - ) => Ok(Box::new(DecimalAvgAccumulator::<Decimal128Type> { - sum: None, - count: 0, - sum_scale: *sum_scale, - sum_precision: *sum_precision, - target_precision: *target_precision, - target_scale: *target_scale, - })), - - ( - Decimal256(sum_precision, sum_scale), - Decimal256(target_precision, target_scale), - ) => Ok(Box::new(DecimalAvgAccumulator::<Decimal256Type> { - sum: None, - count: 0, - sum_scale: *sum_scale, - sum_precision: *sum_precision, - target_precision: *target_precision, - target_scale: *target_scale, - })), - - (Duration(time_unit), Duration(result_unit)) => { - Ok(Box::new(DurationAvgAccumulator { + if acc_args.is_distinct { + match &data_type { + // Numeric types are converted to Float64 via `coerce_avg_type` during logical plan creation + Float64 => Ok(Box::new(Float64DistinctAvgAccumulator::default())), + _ => exec_err!("AVG(DISTINCT) for {} not supported", data_type), + } + } else { + match (&data_type, acc_args.return_field.data_type()) { + (Float64, Float64) => Ok(Box::<AvgAccumulator>::default()), + ( + Decimal128(sum_precision, sum_scale), + Decimal128(target_precision, target_scale), + ) => Ok(Box::new(DecimalAvgAccumulator::<Decimal128Type> { sum: None, count: 0, - time_unit: *time_unit, - result_unit: *result_unit, - })) - } + sum_scale: *sum_scale, + sum_precision: *sum_precision, + target_precision: *target_precision, + target_scale: *target_scale, + })), + + ( + Decimal256(sum_precision, sum_scale), + Decimal256(target_precision, target_scale), + ) => Ok(Box::new(DecimalAvgAccumulator::<Decimal256Type> { + sum: None, + count: 0, + sum_scale: *sum_scale, + sum_precision: *sum_precision, + target_precision: *target_precision, + target_scale: *target_scale, + })), + + (Duration(time_unit), Duration(result_unit)) => { + Ok(Box::new(DurationAvgAccumulator { + sum: None, + count: 0, + time_unit: *time_unit, + result_unit: *result_unit, + })) + } - _ => exec_err!( - "AvgAccumulator for ({} --> {})", - &data_type, - acc_args.return_field.data_type() - ), + _ => exec_err!( + "AvgAccumulator for ({} --> {})", + &data_type, + acc_args.return_field.data_type() + ), + } } } fn state_fields(&self, args: StateFieldsArgs) -> Result<Vec<FieldRef>> { - Ok(vec![ - Field::new( - format_state_name(args.name, "count"), - DataType::UInt64, - true, - ), - Field::new( - format_state_name(args.name, "sum"), - args.input_fields[0].data_type().clone(), - true, - ), - ] - .into_iter() - .map(Arc::new) - .collect()) + if args.is_distinct { + // Copied from datafusion_functions_aggregate::sum::Sum::state_fields + // since the accumulator uses DistinctSumAccumulator internally. + Ok(vec![Field::new_list( + format_state_name(args.name, "sum distinct"), + Field::new_list_field(args.return_type().clone(), true), + false, + ) + .into()]) + } else { + Ok(vec![ + Field::new( + format_state_name(args.name, "count"), + DataType::UInt64, + true, + ), + Field::new( + format_state_name(args.name, "sum"), + args.input_fields[0].data_type().clone(), + true, + ), + ] + .into_iter() + .map(Arc::new) + .collect()) + } Review Comment: I don't really understand this question -- the PR's code looks good to me -- This is an automated message from the Apache Git Service. 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