Imported Upstream version 2.0.6

1 files changed, 33 insertions, 18 deletions

diff --git a/db/queryoptimizer.cpp b/db/queryoptimizer.cpp
index 71ca657..8ec4cb4 100644
--- a/db/queryoptimizer.cpp
+++ b/db/queryoptimizer.cpp
@@ -214,22 +214,6 @@ doneCheckOrder:
         if ( willScanTable() ) {
             if ( _frs.nNontrivialRanges() ) {
                 checkTableScanAllowed( _frs.ns() );
-                
-                // if we are doing a table scan on _id
-                // and its a capped collection
-                // we disallow as its a common user error
-                // .system. and local collections are exempt
-                if ( _d && _d->capped && _frs.range( "_id" ).nontrivial() ) {
-                    if ( cc().isSyncThread() ||
-                         str::contains( _frs.ns() , ".system." ) || 
-                         str::startsWith( _frs.ns() , "local." ) ) {
-                        // ok
-                    }
-                    else {
-                        warning() << "_id query on capped collection without an _id index, performance will be poor collection: " << _frs.ns() << endl;
-                        //uassert( 14820, str::stream() << "doing _id query on a capped collection without an index is not allowed: " << _frs.ns() ,
-                    }
-                }
             }
             return findTableScan( _frs.ns(), _order, startLoc );
         }
@@ -486,12 +470,14 @@ doneCheckOrder:
                     _usingPrerecordedPlan = true;
                     _mayRecordPlan = false;
                     _plans.push_back( p );
+                    warnOnCappedIdTableScan();
                     return;
                 }
             }
         }
 
         addOtherPlans( false );
+        warnOnCappedIdTableScan();
     }
 
     void QueryPlanSet::addOtherPlans( bool checkFirst ) {
@@ -633,6 +619,31 @@ doneCheckOrder:
         }
         return _plans[0];
     }
+    
+    void QueryPlanSet::warnOnCappedIdTableScan() const {
+        // if we are doing a table scan on _id
+        // and it's a capped collection
+        // we warn as it's a common user error
+        // .system. and local collections are exempt
+        const char *ns = _frsp->ns();
+        NamespaceDetails *d = nsdetails( ns );
+        if ( d &&
+            d->capped &&
+            nPlans() == 1 &&
+            firstPlan()->willScanTable() &&
+            firstPlan()->multikeyFrs().range( "_id" ).nontrivial() ) {
+            if ( cc().isSyncThread() ||
+                str::contains( ns , ".system." ) ||
+                str::startsWith( ns , "local." ) ) {
+                // ok
+            }
+            else {
+                warning()
+                << "unindexed _id query on capped collection, "
+                << "performance will be poor collection: " << ns << endl;
+            }
+        }
+    }
 
     QueryPlanSet::Runner::Runner( QueryPlanSet &plans, QueryOp &op ) :
         _op( op ),
@@ -1247,8 +1258,12 @@ doneCheckOrder:
     void QueryUtilIndexed::clearIndexesForPatterns( const FieldRangeSetPair &frsp, const BSONObj &order ) {
         SimpleMutex::scoped_lock lk(NamespaceDetailsTransient::_qcMutex);
         NamespaceDetailsTransient& nsd = NamespaceDetailsTransient::get_inlock( frsp.ns() );
-        nsd.registerIndexForPattern( frsp._singleKey.pattern( order ), BSONObj(), 0 );
-        nsd.registerIndexForPattern( frsp._multiKey.pattern( order ), BSONObj(), 0 );
+        if ( frsp._singleKey.matchPossible() ) {
+            nsd.registerIndexForPattern( frsp._singleKey.pattern( order ), BSONObj(), 0 );
+        }
+        if ( frsp._multiKey.matchPossible() ) {
+            nsd.registerIndexForPattern( frsp._multiKey.pattern( order ), BSONObj(), 0 );
+        }
     }
     
     pair< BSONObj, long long > QueryUtilIndexed::bestIndexForPatterns( const FieldRangeSetPair &frsp, const BSONObj &order ) {