add extra logging

processing/src/main/java/io/druid/segment/IndexMaker.java

@@ -819,7 +819,6 @@ public class IndexMaker
       final List<IntBuffer> rowNumConversions
   ) throws IOException
   {
-
     final String section = String.format("make %s", dimension);
     progress.startSection(section);
 
@@ -1181,6 +1180,8 @@ public class IndexMaker
       spatialIndex = ImmutableRTree.newImmutableFromMutable(tree);
     }
 
+    log.info("Completed dimension[%s] with cardinality[%,d]. Starting write.", dimension, dictionary.size());
+
     writeColumn(
         v9Smoosher,
         new DictionaryEncodedColumnPartSerde(