added default value for dataset cardinality hint

git-svn-id: https://asterixdb.googlecode.com/svn/branches/asterix_stabilization_issue_251@1109 eaa15691-b419-025a-1212-ee371bd00084
diff --git a/asterix-algebra/src/main/java/edu/uci/ics/asterix/translator/DatasetHints.java b/asterix-algebra/src/main/java/edu/uci/ics/asterix/translator/DatasetHints.java
index 4836302..6ebdd35 100644
--- a/asterix-algebra/src/main/java/edu/uci/ics/asterix/translator/DatasetHints.java
+++ b/asterix-algebra/src/main/java/edu/uci/ics/asterix/translator/DatasetHints.java
@@ -56,11 +56,13 @@
 }
 
 /**
- * Represents the expected number of tuples in the dataset.
+ * Hint representing the expected number of tuples in the dataset.
  */
 class DatasetCardinalityHint implements IHint {
     private static final String name = "CARDINALITY";
 
+    public static final long DEFAULT = 1000000L;
+
     @Override
     public String getName() {
         return name;