Merge branch 'develop'
diff --git a/.gitignore b/.gitignore
index ea4e89d..295cafd 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,4 @@
 data/sample_movielens_data.txt
 manifest.json
+target/
+pio.log
diff --git a/src/main/scala/DataSource.scala b/src/main/scala/DataSource.scala
index bad619c..23faa3d 100644
--- a/src/main/scala/DataSource.scala
+++ b/src/main/scala/DataSource.scala
@@ -49,7 +49,8 @@
         }
       }
       rating
-    }
+    }.cache()
+
     new TrainingData(ratingsRDD)
   }
 }