Short-circuit if re-calc eliminates needs for union.

1 files changed, 10 insertions, 0 deletions

diff --git a/src/main/java/com/amazon/carbonado/qe/UnionQueryAnalyzer.java b/src/main/java/com/amazon/carbonado/qe/UnionQueryAnalyzer.java
index 2f467eb..9ed94fd 100644
--- a/src/main/java/com/amazon/carbonado/qe/UnionQueryAnalyzer.java
+++ b/src/main/java/com/amazon/carbonado/qe/UnionQueryAnalyzer.java
@@ -111,6 +111,11 @@ public class UnionQueryAnalyzer<S extends Storable> {
             // Re-calc with specified direction. Only do one property at a time

             // since one simple change might alter the query plan.

             subResults = splitIntoSubResults(filter, orderings);

+

+            if (subResults.size() < 1) {

+                // Total ordering no longer required.

+                return new Result(subResults);

+            }

         }

 

         // Gather all the keys available. As ordering properties touch key

@@ -178,6 +183,11 @@ public class UnionQueryAnalyzer<S extends Storable> {
             orderings.add(OrderedProperty.get(bestProperty, best.getBestDirection()));

             subResults = splitIntoSubResults(filter, orderings);

 

+            if (subResults.size() < 1) {

+                // Total ordering no longer required.

+                break;

+            }

+

             // Remove property from super key and key set...

             superKey.remove(bestProperty);

             if (superKey.size() == 0) {