1 files changed, 2 insertions, 8 deletions
diff --git a/src/mongo/db/query/plan_enumerator.h b/src/mongo/db/query/plan_enumerator.h
index 8b563ed145b..53643b2a95c 100644
--- a/src/mongo/db/query/plan_enumerator.h
+++ b/src/mongo/db/query/plan_enumerator.h
@@ -430,16 +430,10 @@ private:
      */
     bool alreadyCompounded(const std::set<MatchExpression*>& ixisectAssigned,
                            const AndAssignment* andAssignment);
-
-    struct CmpByIndexID {
-        bool operator()(IndexID a, IndexID b) const {
-            return a < b;
-        }
-    };
     /**
-     * Maps from index id to the list of predicates assigned to that index.
+     * Output index intersection assignments inside of an AND node.
      */
-    typedef std::map<IndexID, std::vector<MatchExpression*>, CmpByIndexID> IndexToPredMap;
+    typedef unordered_map<IndexID, std::vector<MatchExpression*>> IndexToPredMap;
 
     /**
      * Generate index intersection assignments given the predicate/index structure in idxToFirst