Index: lucene/CHANGES.txt
===================================================================
--- lucene/CHANGES.txt	(revision 1450291)
+++ lucene/CHANGES.txt	(working copy)
@@ -271,6 +271,8 @@
   AnalysisSPILoader when doing reload (e.g. from Solr).
   (Uwe Schindler, Hossman)
 
+* LUCENE-4802: Don't compute norms for drill-down facet fields. (Mike McCandless)
+
 Documentation
 
 * LUCENE-4718: Fixed documentation of oal.queryparser.classic.
Index: lucene/facet/src/test/org/apache/lucene/facet/search/TestDemoFacets.java
===================================================================
--- lucene/facet/src/test/org/apache/lucene/facet/search/TestDemoFacets.java	(revision 1450291)
+++ lucene/facet/src/test/org/apache/lucene/facet/search/TestDemoFacets.java	(working copy)
@@ -21,15 +21,19 @@
 import java.io.IOException;
 import java.io.PrintStream;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 
+import org.apache.lucene.analysis.MockAnalyzer;
 import org.apache.lucene.document.Document;
+import org.apache.lucene.document.Field;
 import org.apache.lucene.facet.FacetTestCase;
 import org.apache.lucene.facet.FacetTestUtils;
 import org.apache.lucene.facet.index.FacetFields;
 import org.apache.lucene.facet.params.FacetSearchParams;
 import org.apache.lucene.facet.taxonomy.CategoryPath;
 import org.apache.lucene.facet.taxonomy.TaxonomyReader;
+import org.apache.lucene.facet.taxonomy.TaxonomyWriter;
 import org.apache.lucene.facet.taxonomy.directory.DirectoryTaxonomyReader;
 import org.apache.lucene.facet.taxonomy.directory.DirectoryTaxonomyWriter;
 import org.apache.lucene.facet.util.PrintTaxonomyStats;
@@ -37,6 +41,9 @@
 import org.apache.lucene.index.RandomIndexWriter;
 import org.apache.lucene.search.IndexSearcher;
 import org.apache.lucene.search.MatchAllDocsQuery;
+import org.apache.lucene.search.similarities.DefaultSimilarity;
+import org.apache.lucene.search.similarities.PerFieldSimilarityWrapper;
+import org.apache.lucene.search.similarities.Similarity;
 import org.apache.lucene.store.Directory;
 
 public class TestDemoFacets extends FacetTestCase {
@@ -134,4 +141,30 @@
     taxoDir.close();
   }
 
+  public void testReallyNoNormsForDrillDown() throws Exception {
+    Directory dir = newDirectory();
+    Directory taxoDir = newDirectory();
+    IndexWriterConfig iwc = newIndexWriterConfig(TEST_VERSION_CURRENT, new MockAnalyzer(random()));
+    iwc.setSimilarity(new PerFieldSimilarityWrapper() {
+        final Similarity sim = new DefaultSimilarity();
+
+        @Override
+        public Similarity get(String name) {
+          assertEquals("field", name);
+          return sim;
+        }
+      });
+    RandomIndexWriter writer = new RandomIndexWriter(random(), dir, iwc);
+    TaxonomyWriter taxoWriter = new DirectoryTaxonomyWriter(taxoDir, IndexWriterConfig.OpenMode.CREATE);
+    FacetFields facetFields = new FacetFields(taxoWriter);      
+
+    Document doc = new Document();
+    doc.add(newTextField("field", "text", Field.Store.NO));
+    facetFields.addFields(doc, Collections.singletonList(new CategoryPath("a/path", '/')));
+    writer.addDocument(doc);
+    writer.close();
+    taxoWriter.close();
+    dir.close();
+    taxoDir.close();
+  }
 }
Index: lucene/facet/src/java/org/apache/lucene/facet/index/FacetFields.java
===================================================================
--- lucene/facet/src/java/org/apache/lucene/facet/index/FacetFields.java	(revision 1450291)
+++ lucene/facet/src/java/org/apache/lucene/facet/index/FacetFields.java	(working copy)
@@ -5,8 +5,8 @@
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
+import java.util.Map.Entry;
 import java.util.Map;
-import java.util.Map.Entry;
 
 import org.apache.lucene.document.BinaryDocValuesField;
 import org.apache.lucene.document.Document;
@@ -66,6 +66,7 @@
   private static final FieldType DRILL_DOWN_TYPE = new FieldType(TextField.TYPE_NOT_STORED);
   static {
     DRILL_DOWN_TYPE.setIndexOptions(IndexOptions.DOCS_ONLY);
+    DRILL_DOWN_TYPE.setOmitNorms(true);
     DRILL_DOWN_TYPE.freeze();
   }