Remove a hacky code.
diff --git a/asterix-common/src/main/java/edu/uci/ics/asterix/common/context/PrimaryIndexOperationTracker.java b/asterix-common/src/main/java/edu/uci/ics/asterix/common/context/PrimaryIndexOperationTracker.java
index 53b9192..218af58 100644
--- a/asterix-common/src/main/java/edu/uci/ics/asterix/common/context/PrimaryIndexOperationTracker.java
+++ b/asterix-common/src/main/java/edu/uci/ics/asterix/common/context/PrimaryIndexOperationTracker.java
@@ -62,8 +62,8 @@
     public void afterOperation(ILSMIndex index, LSMOperationType opType, ISearchOperationCallback searchCallback,
             IModificationOperationCallback modificationCallback) throws HyracksDataException {
         // Searches are immediately considered complete, because they should not prevent the execution of flushes.
-        if ((searchCallback != null && searchCallback != NoOpOperationCallback.INSTANCE)
-                || opType == LSMOperationType.FLUSH || opType == LSMOperationType.MERGE) {
+        if (opType == LSMOperationType.SEARCH || opType == LSMOperationType.NOOP || opType == LSMOperationType.FLUSH
+                || opType == LSMOperationType.MERGE) {
             completeOperation(index, opType, searchCallback, modificationCallback);
         }
     }