Better readme!

README.md

@@ -1,4 +1,21 @@
 DualInputFormat
 ===============
 
-An input format that returns a single split with a single role
+An input format that returns a single split with a single row.
+
+Can be used from hive like this.
+
+    client.execute ( "add jar "+jarFile);
+    client.execute("create table  dual  (fake string) "+
+            "STORED AS INPUTFORMAT 'com.m6d.dualinputformat.DualInputFormat'"+
+            "OUTPUTFORMAT 'org.apache.hadoop.hive.ql.io.HiveIgnoreKeyTextOutputFormat'");
+    client.execute("load data local inpath '" + p.toString() + "' into table dual");
+    client.execute("select count(1) as cnt from dual");
+    String row = client.fetchOne();
+    assertEquals( "1", row);
+
+    client.execute("select * from dual");
+    row = client.fetchOne();
+    assertEquals( "", row);
+
+    client.execute("drop table dual");