push filters down into join condition

Author: angelamayxie

sql/analyzer/pushdown.go

@@ -339,5 +339,14 @@ func removePushedDownPredicates(ctx *sql.Context, a *Analyzer, node *plan.Filter
 		unhandled,
 	)
 
+	if joinChild, ok := node.Child.(*plan.JoinNode); ok && !joinChild.Op.IsOuter() {
+		if joinChild.Op.IsCross() {
+			return plan.NewInnerJoin(joinChild.Left(), joinChild.Right(), expression.JoinAnd(unhandled...))
+		}
+		unhandled = append(unhandled, joinChild.Filter)
+		joinChild.Filter = expression.JoinAnd(unhandled...)
+		return joinChild
+	}
+
 	return plan.NewFilter(expression.JoinAnd(unhandled...), node.Child)
 }

sql/plan/join.go

@@ -68,6 +68,10 @@ const (
 	JoinTypeLateralRight // LateralLeftJoin
 )
 
+func (i JoinType) IsOuter() bool {
+	return i.IsLeftOuter() || i.IsRightOuter() || i.IsFullOuter()
+}
+
 func (i JoinType) IsLeftOuter() bool {
 	switch i {
 	case JoinTypeLeftOuter, JoinTypeLeftOuterExcludeNulls, JoinTypeLeftOuterLookup, JoinTypeLeftOuterHash, JoinTypeLeftOuterHashExcludeNulls, JoinTypeLeftOuterMerge, JoinTypeLeftOuterRangeHeap: