func (b *executorBuilder) newAggFuncToPBExpr(client kv.Client, aggFunc expression.AggregationFunction,
tbl *model.TableInfo) *tipb.Expr {
var tp tipb.ExprType
switch aggFunc.GetName() {
case ast.AggFuncCount:
tp = tipb.ExprType_Count
case ast.AggFuncFirstRow:
tp = tipb.ExprType_First
case ast.AggFuncGroupConcat:
tp = tipb.ExprType_GroupConcat
case ast.AggFuncMax:
tp = tipb.ExprType_Max
case ast.AggFuncMin:
tp = tipb.ExprType_Min
case ast.AggFuncSum:
tp = tipb.ExprType_Sum
case ast.AggFuncAvg:
tp = tipb.ExprType_Avg
}
if !client.SupportRequestType(kv.ReqTypeSelect, int64(tp)) {
return nil
}
children := make([]*tipb.Expr, 0, len(aggFunc.GetArgs()))
for _, arg := range aggFunc.GetArgs() {
pbArg := b.newExprToPBExpr(client, arg, tbl)
if pbArg == nil {
return nil
}
children = append(children, pbArg)
}
return &tipb.Expr{Tp: tp.Enum(), Children: children}
}
func aggFuncToPBExpr(sc *variable.StatementContext, client kv.Client, aggFunc expression.AggregationFunction) *tipb.Expr {
pc := pbConverter{client: client, sc: sc}
var tp tipb.ExprType
switch aggFunc.GetName() {
case ast.AggFuncCount:
tp = tipb.ExprType_Count
case ast.AggFuncFirstRow:
tp = tipb.ExprType_First
case ast.AggFuncGroupConcat:
tp = tipb.ExprType_GroupConcat
case ast.AggFuncMax:
tp = tipb.ExprType_Max
case ast.AggFuncMin:
tp = tipb.ExprType_Min
case ast.AggFuncSum:
tp = tipb.ExprType_Sum
case ast.AggFuncAvg:
tp = tipb.ExprType_Avg
}
if !client.SupportRequestType(kv.ReqTypeSelect, int64(tp)) {
return nil
}
children := make([]*tipb.Expr, 0, len(aggFunc.GetArgs()))
for _, arg := range aggFunc.GetArgs() {
pbArg := pc.exprToPB(arg)
if pbArg == nil {
return nil
}
children = append(children, pbArg)
}
return &tipb.Expr{Tp: tp, Children: children}
}
// getAggFuncChildIdx gets which children it belongs to, 0 stands for left, 1 stands for right, -1 stands for both.
func (a *aggPushDownSolver) getAggFuncChildIdx(aggFunc expression.AggregationFunction, schema expression.Schema) int {
fromLeft, fromRight := false, false
var cols []*expression.Column
for _, arg := range aggFunc.GetArgs() {
cols = append(cols, expression.ExtractColumns(arg)...)
}
for _, col := range cols {
if schema.GetIndex(col) != -1 {
fromLeft = true
} else {
fromRight = true
}
}
if fromLeft && fromRight {
return -1
} else if fromLeft {
return 0
}
return 1
}