bail out or clause checking if we do an unpredicted table scan

mongodb · Jul 20, 2010 · decb87e · decb87e
1 parent 4760c02
commit decb87e
Show file tree

Hide file tree

Showing 3 changed files with 9 additions and 3 deletions.
diff --git a/db/queryoptimizer.cpp b/db/queryoptimizer.cpp
@@ -641,7 +641,8 @@ namespace mongo {
     _honorRecordedPlan( honorRecordedPlan ),
     _bestGuessOnly( bestGuessOnly ),
     _hint( ( hint && !hint->eoo() ) ? hint->wrap() : BSONObj() ),
-    _mayYield( mayYield )
+    _mayYield( mayYield ),
+    _tableScanned()
     {
         if ( !order.isEmpty() || !min.isEmpty() || !max.isEmpty() || !_fros.getSpecial().empty() ) {
             _or = false;
@@ -670,6 +671,9 @@ namespace mongo {
         BSONElement hintElt = _hint.firstElement();
         _currentQps.reset( new QueryPlanSet( _ns, frs, _query, BSONObj(), &hintElt, _honorRecordedPlan, BSONObj(), BSONObj(), _bestGuessOnly, _mayYield ) );
         shared_ptr< QueryOp > ret( _currentQps->runOp( op ) );
+        if ( ret->qp().willScanTable() ) {
+            _tableScanned = true;
+        }
         _fros.popOrClause();
         return ret;
     }

diff --git a/db/queryoptimizer.h b/db/queryoptimizer.h
@@ -55,6 +55,7 @@ namespace mongo {
         shared_ptr<Cursor> newCursor( const DiskLoc &startLoc = DiskLoc() , int numWanted=0 ) const;
         shared_ptr<Cursor> newReverseCursor() const;
         BSONObj indexKey() const;
+        bool willScanTable() const { return !index_ && fbs_.matchPossible(); }
         const char *ns() const { return fbs_.ns(); }
         NamespaceDetails *nsd() const { return d; }
         BSONObj originalQuery() const { return _originalQuery; }
@@ -275,7 +276,7 @@ namespace mongo {
         shared_ptr< T > runOpOnce( T &op ) {
             return dynamic_pointer_cast< T >( runOpOnce( static_cast< QueryOp& >( op ) ) );
         }       
-        bool mayRunMore() const { return _or ? !_fros.orFinished() : _i == 0; }
+        bool mayRunMore() const { return _or ? ( !_tableScanned && !_fros.orFinished() ) : _i == 0; }
         BSONObj oldExplain() const { assertNotOr(); return _currentQps->explain(); }
         // just report this when only one query op
         bool usingPrerecordedPlan() const {
@@ -298,6 +299,7 @@ namespace mongo {
         bool _bestGuessOnly;
         BSONObj _hint;
         bool _mayYield;
+        bool _tableScanned;
     };
 
     class MultiCursor : public Cursor {

diff --git a/jstests/or9.js b/jstests/or9.js
@@ -24,7 +24,7 @@ check( 1, 2, { $or: [ { a: { $gt:2,$lte:3 } }, { a: 2 } ] } );
 
 check( 1, 1, { $or: [ { b: { $gte:1,$lte:3 } }, { b: 2 } ] } );
 check( 1, 1, { $or: [ { b: { $gte:2,$lte:3 } }, { b: 2 } ] } );
-//check( 1, 2, { $or: [ { b: { $gt:2,$lte:3 } }, { b: 2 } ] } );
+check( 1, 1, { $or: [ { b: { $gt:2,$lte:3 } }, { b: 2 } ] } );
 
 check( 1, 1, { $or: [ { a: { $gte:1,$lte:3 } }, { a: 2, b: 2 } ] } );
 check( 1, 2, { $or: [ { a: { $gte:1,$lte:3 }, b:3 }, { a: 2 } ] } );