[Bigdata-commit] SF.net SVN: bigdata:[7791] branches/BIGDATA_RELEASE_1_3_0/bigdata/src/java/ com/bigdata/bop/joinGraph/rto/SampleBase.java

[<tho...@us...>]

Revision: 7791
          http://bigdata.svn.sourceforge.net/bigdata/?rev=7791&view=rev
Author:   thompsonbry
Date:     2014-01-14 12:55:58 +0000 (Tue, 14 Jan 2014)
Log Message:
-----------
Added isUnderflow() method.

Modified Paths:
--------------
    branches/BIGDATA_RELEASE_1_3_0/bigdata/src/java/com/bigdata/bop/joinGraph/rto/SampleBase.java

Modified: branches/BIGDATA_RELEASE_1_3_0/bigdata/src/java/com/bigdata/bop/joinGraph/rto/SampleBase.java
===================================================================
--- branches/BIGDATA_RELEASE_1_3_0/bigdata/src/java/com/bigdata/bop/joinGraph/rto/SampleBase.java	2014-01-14 12:55:11 UTC (rev 7790)
+++ branches/BIGDATA_RELEASE_1_3_0/bigdata/src/java/com/bigdata/bop/joinGraph/rto/SampleBase.java	2014-01-14 12:55:58 UTC (rev 7791)
@@ -100,6 +100,20 @@
     }
 
     /**
+     * Return <code>true</code> iff this sample has cardinality underflow (the
+     * sample is empty). Cardinality underflow occurs when the sampling process
+     * was unable to find any solutions. Underflow is typically addressed by
+     * increasing the sample size, but sometimes underflow indicates that an
+     * access path (if it has filters) or a join may not have any solutions in
+     * the data.
+     */
+    public boolean isUnderflow() {
+
+        return estimateEnum == EstimateEnum.Underflow;
+
+    }
+
+    /**
      * Sample.
      */
     private final AtomicReference<IBindingSet[]> sampleRef = new AtomicReference<IBindingSet[]>();

This was sent by the SourceForge.net collaborative development platform, the world's largest Open Source development site.