changed the way we calculate dependencies for ExtractedSubqueries

Signed-off-by: Florent Poinsard <florent.poinsard@outlook.fr>

go/vt/vtgate/planbuilder/abstract/querygraph.go

@@ -133,15 +133,6 @@ func (qg *QueryGraph) addJoinPredicates(ts semantics.TableSet, expr sqlparser.Ex
 
 func (qg *QueryGraph) collectPredicate(predicate sqlparser.Expr, semTable *semantics.SemTable) error {
 	deps := semTable.RecursiveDeps(predicate)
-	extracted, ok := predicate.(*sqlparser.ExtractedSubquery)
-	if ok {
-		// we don't want to look at the subquery dependencies
-		if extracted.OtherSide == nil {
-			deps = semantics.SingleTableSet(0)
-		} else {
-			deps = semTable.RecursiveDeps(extracted.OtherSide)
-		}
-	}
 	switch deps.NumberOfTables() {
 	case 0:
 		qg.addNoDepsPredicate(predicate)

go/vt/vtgate/semantics/semantic_state.go

@@ -230,10 +230,15 @@ func (d ExprDependencies) Dependencies(expr sqlparser.Expr) (deps TableSet) {
 			return true, nil
 		}
 
-		set, found := d[expr]
-		if found {
-			deps.MergeInPlace(set)
+		if extracted, ok := expr.(*sqlparser.ExtractedSubquery); ok {
+			if extracted.OtherSide != nil {
+				set := d.Dependencies(extracted.OtherSide)
+				deps.MergeInPlace(set)
+			}
+			return false, nil
 		}
+		set, found := d[expr]
+		deps.MergeInPlace(set)
 
 		// if we found a cached value, there is no need to continue down to visit children
 		return !found, nil