1 files changed, 28 insertions, 0 deletions
diff --git a/jstests/queryoptimizer6.js b/jstests/queryoptimizer6.js
new file mode 100644
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--- /dev/null
+++ b/jstests/queryoptimizer6.js
@@ -0,0 +1,28 @@
+// Test that $ne constraints are accounted for in QueryPattern. SERVER-4665
+
+t = db.jstests_queryoptimizer6;
+
+function reset() {
+    t.drop();
+    t.save( {a:1} );
+    t.ensureIndex( {b:1}, {sparse:true} );
+}
+
+reset();
+// The sparse index will be used, and recorded for this query pattern.
+assert.eq( 0, t.find( {a:1,b:{$ne:1}} ).itcount() );
+// The query pattern should be different, and the sparse index should not be used.
+assert.eq( 1, t.find( {a:1} ).itcount() );
+
+reset();
+// The sparse index will be used, and (for better or worse) recorded for this query pattern.
+assert.eq( 0, t.find( {a:1} ).min({b:1}).itcount() );
+// The sparse index should not be used, even though the query patterns match.
+assert.eq( 1, t.find( {a:1} ).itcount() );
+
+reset();
+t.ensureIndex( {a:1,b:1} );
+// The sparse index will be used, and (for better or worse) recorded for this query pattern.
+assert.eq( 0, t.find( {a:1,b:null} ).min({b:1}).itcount() );
+// Descriptive test - the recorded {b:1} index is used, because it is not useless.
+assert.eq( 0, t.find( {a:1,b:null} ).itcount() );