diff --git a/worker/mutation.go b/worker/mutation.go
index 002c2adc7a5..e7fecbd9c65 100644
--- a/worker/mutation.go
+++ b/worker/mutation.go
@@ -182,18 +182,15 @@ func runSchemaMutation(ctx context.Context, updates []*pb.SchemaUpdate, startTs
 	var wg sync.WaitGroup
 	wg.Add(1)
 	defer wg.Done()
-	// This throttle allows is used to limit the number of files which are opened simultaneously
-	// by badger while building indexes for predicates in background.
-	maxOpenFileLimit, err := x.QueryMaxOpenFiles()
-	if err != nil {
-		// Setting to default value on unix systems
-		maxOpenFileLimit = 1024
-	}
-	glog.Infof("Max open files limit: %d", maxOpenFileLimit)
+
 	// Badger opens around 8 files for indexing per predicate.
-	// The throttle limit is set to maxOpenFileLimit/8 to ensure that indexing does not throw
-	// "Too many open files" error.
-	throttle := y.NewThrottle(maxOpenFileLimit / 8)
+	// The throttle limit is set to 1024 to ensure that indexing
+	// does not throw "Too many open files" error.
+	maxPredicateAtATime := 1024
+	if len(updates) < maxPredicateAtATime {
+		maxPredicateAtATime = len(updates)
+	}
+	throttle := y.NewThrottle(maxPredicateAtATime)
 
 	buildIndexes := func(update *pb.SchemaUpdate, rebuild posting.IndexRebuild, c *z.Closer) {
 		// In case background indexing is running, we should call it here again.
@@ -237,6 +234,7 @@ func runSchemaMutation(ctx context.Context, updates []*pb.SchemaUpdate, startTs
 
 		// Start opIndexing task only if schema update needs to build the indexes.
 		if shouldRebuild && !gr.Node.isRunningTask(opIndexing) {
+			var err error
 			closer, err = gr.Node.startTaskAtTs(opIndexing, startTs)
 			if err != nil {
 				return err