*: add aggregate function min_count/max_count

pkg/executor/aggfuncs/BUILD.bazel

@@ -16,6 +16,7 @@ go_library(
         "func_json_objectagg.go",
         "func_lead_lag.go",
         "func_max_min.go",
+        "func_max_min_count.go",
         "func_ntile.go",
         "func_percent_rank.go",
         "func_percentile.go",
@@ -73,6 +74,7 @@ go_test(
         "func_json_arrayagg_test.go",
         "func_json_objectagg_test.go",
         "func_lead_lag_test.go",
+        "func_max_min_count_test.go",
         "func_max_min_test.go",
         "func_ntile_test.go",
         "func_percent_rank_test.go",

pkg/executor/aggfuncs/aggfuncs.go

@@ -79,6 +79,18 @@ var (
 	_ AggFunc = (*maxMin4VectorFloat32)(nil)
 	_ AggFunc = (*maxMin4Enum)(nil)
 	_ AggFunc = (*maxMin4Set)(nil)
+	_ AggFunc = (*maxMinCount4Int)(nil)
+	_ AggFunc = (*maxMinCount4Uint)(nil)
+	_ AggFunc = (*maxMinCount4Float32)(nil)
+	_ AggFunc = (*maxMinCount4Float64)(nil)
+	_ AggFunc = (*maxMinCount4Decimal)(nil)
+	_ AggFunc = (*maxMinCount4String)(nil)
+	_ AggFunc = (*maxMinCount4Time)(nil)
+	_ AggFunc = (*maxMinCount4Duration)(nil)
+	_ AggFunc = (*maxMinCount4JSON)(nil)
+	_ AggFunc = (*maxMinCount4VectorFloat32)(nil)
+	_ AggFunc = (*maxMinCount4Enum)(nil)
+	_ AggFunc = (*maxMinCount4Set)(nil)
 
 	// All the AggFunc implementations for "AVG" are listed here.
 	_ AggFunc = (*avgOriginal4Decimal)(nil)

pkg/executor/aggfuncs/builder.go

@@ -50,6 +50,10 @@ func Build(ctx AggFuncBuildContext, aggFuncDesc *aggregation.AggFuncDesc, ordina
 		return buildMaxMin(aggFuncDesc, ordinal, true)
 	case ast.AggFuncMin:
 		return buildMaxMin(aggFuncDesc, ordinal, false)
+	case ast.AggFuncMaxCount:
+		return buildMaxMinCount(ctx.GetEvalCtx(), aggFuncDesc, ordinal, true)
+	case ast.AggFuncMinCount:
+		return buildMaxMinCount(ctx.GetEvalCtx(), aggFuncDesc, ordinal, false)
 	case ast.AggFuncGroupConcat:
 		return buildGroupConcat(ctx, aggFuncDesc, ordinal)
 	case ast.AggFuncBitOr:
@@ -108,6 +112,10 @@ func BuildWindowFunctions(ctx AggFuncBuildContext, windowFuncDesc *aggregation.A
 		return buildMaxMinInWindowFunction(ctx, windowFuncDesc, ordinal, true)
 	case ast.AggFuncMin:
 		return buildMaxMinInWindowFunction(ctx, windowFuncDesc, ordinal, false)
+	case ast.AggFuncMaxCount:
+		return buildMaxMinCountInWindowFunction(ctx, windowFuncDesc, ordinal, true)
+	case ast.AggFuncMinCount:
+		return buildMaxMinCountInWindowFunction(ctx, windowFuncDesc, ordinal, false)
 	default:
 		return Build(ctx, windowFuncDesc, ordinal)
 	}
@@ -470,6 +478,64 @@ func buildMaxMin(aggFuncDesc *aggregation.AggFuncDesc, ordinal int, isMax bool)
 	return nil
 }
 
+// buildMaxMinCount builds the AggFunc implementation for function "MAX_COUNT" and "MIN_COUNT".
+func buildMaxMinCount(ctx expression.EvalContext, aggFuncDesc *aggregation.AggFuncDesc, ordinal int, isMax bool) AggFunc {
+	if aggFuncDesc.Mode == aggregation.DedupMode {
+		return nil
+	}
+
+	argTp := aggFuncDesc.Args[0].GetType(ctx)
+	base := baseMaxMinCountAggFunc{
+		baseMaxMinAggFunc: baseMaxMinAggFunc{
+			baseAggFunc: baseAggFunc{
+				args:    aggFuncDesc.Args,
+				ordinal: ordinal,
+				retTp:   aggFuncDesc.RetTp,
+			},
+			isMax:    isMax,
+			collator: collate.GetCollator(argTp.GetCollate()),
+		},
+	}
+	evalType, fieldType := argTp.EvalType(), argTp
+	if fieldType.GetType() == mysql.TypeBit {
+		evalType = types.ETString
+	}
+	switch fieldType.GetType() {
+	case mysql.TypeEnum:
+		return &maxMinCount4Enum{base}
+	case mysql.TypeSet:
+		return &maxMinCount4Set{base}
+	}
+
+	switch evalType {
+	case types.ETInt:
+		if mysql.HasUnsignedFlag(fieldType.GetFlag()) {
+			return &maxMinCount4Uint{base}
+		}
+		return &maxMinCount4Int{base}
+	case types.ETReal:
+		switch fieldType.GetType() {
+		case mysql.TypeFloat:
+			return &maxMinCount4Float32{base}
+		case mysql.TypeDouble:
+			return &maxMinCount4Float64{base}
+		}
+	case types.ETDecimal:
+		return &maxMinCount4Decimal{base}
+	case types.ETString:
+		return &maxMinCount4String{baseMaxMinCountAggFunc: base}
+	case types.ETDatetime, types.ETTimestamp:
+		return &maxMinCount4Time{base}
+	case types.ETDuration:
+		return &maxMinCount4Duration{base}
+	case types.ETJson:
+		return &maxMinCount4JSON{base}
+	case types.ETVectorFloat32:
+		return &maxMinCount4VectorFloat32{base}
+	}
+	return nil
+}
+
 // buildMaxMin builds the AggFunc implementation for function "MAX" and "MIN" using by window function.
 func buildMaxMinInWindowFunction(ctx AggFuncBuildContext, aggFuncDesc *aggregation.AggFuncDesc, ordinal int, isMax bool) AggFunc {
 	base := buildMaxMin(aggFuncDesc, ordinal, isMax)
@@ -495,6 +561,31 @@ func buildMaxMinInWindowFunction(ctx AggFuncBuildContext, aggFuncDesc *aggregati
 	return base
 }
 
+// buildMaxMinCountInWindowFunction builds the AggFunc implementation for function "MAX_COUNT" and "MIN_COUNT" used by window function.
+func buildMaxMinCountInWindowFunction(ctx AggFuncBuildContext, aggFuncDesc *aggregation.AggFuncDesc, ordinal int, isMax bool) AggFunc {
+	base := buildMaxMinCount(ctx.GetEvalCtx(), aggFuncDesc, ordinal, isMax)
+	// build max_count/min_count aggFunc for window function using sliding window
+	switch baseAggFunc := base.(type) {
+	case *maxMinCount4Int:
+		return &maxMinCount4IntSliding{*baseAggFunc, windowInfo{}}
+	case *maxMinCount4Uint:
+		return &maxMinCount4UintSliding{*baseAggFunc, windowInfo{}}
+	case *maxMinCount4Float32:
+		return &maxMinCount4Float32Sliding{*baseAggFunc, windowInfo{}}
+	case *maxMinCount4Float64:
+		return &maxMinCount4Float64Sliding{*baseAggFunc, windowInfo{}}
+	case *maxMinCount4Decimal:
+		return &maxMinCount4DecimalSliding{*baseAggFunc, windowInfo{}}
+	case *maxMinCount4String:
+		return &maxMinCount4StringSliding{*baseAggFunc, windowInfo{}, baseAggFunc.args[0].GetType(ctx.GetEvalCtx()).GetCollate()}
+	case *maxMinCount4Time:
+		return &maxMinCount4TimeSliding{*baseAggFunc, windowInfo{}}
+	case *maxMinCount4Duration:
+		return &maxMinCount4DurationSliding{*baseAggFunc, windowInfo{}}
+	}
+	return base
+}
+
 // buildGroupConcat builds the AggFunc implementation for function "GROUP_CONCAT".
 func buildGroupConcat(ctx AggFuncBuildContext, aggFuncDesc *aggregation.AggFuncDesc, ordinal int) AggFunc {
 	switch aggFuncDesc.Mode {

pkg/executor/aggfuncs/func_max_min.go

@@ -1378,7 +1378,7 @@ func (e *maxMin4TimeSliding) deserializeForSpill(helper *deserializeHelper) (Par
 	return pr, memDelta
 }
 
-var _ SlidingWindowAggFunc = &maxMin4DurationSliding{}
+var _ SlidingWindowAggFunc = &maxMin4TimeSliding{}
 
 func (e *maxMin4TimeSliding) Slide(sctx AggFuncUpdateContext, getRow func(uint64) chunk.Row, lastStart, lastEnd uint64, shiftStart, shiftEnd uint64, pr PartialResult) error {
 	p := (*partialResult4MaxMinTime)(pr)
@@ -1728,6 +1728,26 @@ func (e *maxMin4VectorFloat32) MergePartialResult(_ AggFuncUpdateContext, src, d
 	return 0, nil
 }
 
+func (e *maxMin4VectorFloat32) SerializePartialResult(partialResult PartialResult, chk *chunk.Chunk, spillHelper *SerializeHelper) {
+	pr := (*partialResult4MaxMinVectorFloat32)(partialResult)
+	resBuf := spillHelper.serializePartialResult4MaxMinVectorFloat32(*pr)
+	chk.AppendBytes(e.ordinal, resBuf)
+}
+
+func (e *maxMin4VectorFloat32) DeserializePartialResult(src *chunk.Chunk) ([]PartialResult, int64) {
+	return deserializePartialResultCommon(src, e.ordinal, e.deserializeForSpill)
+}
+
+func (e *maxMin4VectorFloat32) deserializeForSpill(helper *deserializeHelper) (PartialResult, int64) {
+	pr, memDelta := e.AllocPartialResult()
+	result := (*partialResult4MaxMinVectorFloat32)(pr)
+	success := helper.deserializePartialResult4MaxMinVectorFloat32(result)
+	if !success {
+		return nil, 0
+	}
+	return pr, memDelta
+}
+
 type maxMin4Enum struct {
 	baseMaxMinAggFunc
 }