Aggregate Expressions

Average

The following cases are not supported by Comet:

• YearMonthIntervalType and DayTimeIntervalType inputs are not supported

CollectSet

The following incompatibilities cause CollectSet to fall back to Spark by default. Set spark.comet.expression.CollectSet.allowIncompatible=true to enable Comet acceleration despite these differences.

• Comet deduplicates NaN values (treats NaN == NaN) while Spark treats each NaN as a distinct value. When spark.comet.exec.strictFloatingPoint=true, collect_set on floating-point types falls back to Spark unless spark.comet.expression.CollectSet.allowIncompatible=true is set.

First

The following differences from Spark are always present and do not require any additional configuration:

• This function is not deterministic. Results may not match Spark.

Last

The following differences from Spark are always present and do not require any additional configuration:

• This function is not deterministic. Results may not match Spark.