SERVER-4665 backport 'ConstraintPresent' constraint type and exclusion of unhelpful recorded plans

3 files changed, 5 insertions, 2 deletions

diff --git a/db/queryoptimizer.cpp b/db/queryoptimizer.cpp
index 692e9fd9b98..71ca6576fc4 100644
--- a/db/queryoptimizer.cpp
+++ b/db/queryoptimizer.cpp
@@ -482,7 +482,7 @@ doneCheckOrder:
                 }
 
                 massert( 10368 ,  "Unable to locate previously recorded index", p.get() );
-                if ( !( _bestGuessOnly && p->scanAndOrderRequired() ) ) {
+                if ( !p->unhelpful() && !( _bestGuessOnly && p->scanAndOrderRequired() ) ) {
                     _usingPrerecordedPlan = true;
                     _mayRecordPlan = false;
                     _plans.push_back( p );
diff --git a/db/querypattern.h b/db/querypattern.h
index d87cc64a5bc..2f7450e5ec2 100644
--- a/db/querypattern.h
+++ b/db/querypattern.h
@@ -36,7 +36,8 @@ namespace mongo {
             Equality,
             LowerBound,
             UpperBound,
-            UpperAndLowerBound
+            UpperAndLowerBound,
+            ConstraintPresent
         };
         bool operator<( const QueryPattern &other ) const;
         /** for testing only */
diff --git a/db/queryutil.cpp b/db/queryutil.cpp
index 717eac816b8..ef5ae3a6fdb 100644
--- a/db/queryutil.cpp
+++ b/db/queryutil.cpp
@@ -1007,6 +1007,8 @@ namespace mongo {
                     qp._fieldTypes[ i->first ] = QueryPattern::UpperBound;
                 else if ( lower )
                     qp._fieldTypes[ i->first ] = QueryPattern::LowerBound;
+                else
+                    qp._fieldTypes[ i->first ] = QueryPattern::ConstraintPresent;
             }
         }
         qp.setSort( sort );