diff --git a/source/libs/executor/src/groupcacheoperator.c b/source/libs/executor/src/groupcacheoperator.c
index 7a55b42e1a..f56fc98285 100755
--- a/source/libs/executor/src/groupcacheoperator.c
+++ b/source/libs/executor/src/groupcacheoperator.c
@@ -583,7 +583,7 @@ static int32_t getBlkFromSessionCacheImpl(struct SOperatorInfo* pOperator, int64
         pSession->lastBlkId = 0;
         return code;
       }
-    } else if (pSession->lastBlkId < blkNum) {
+    } else if ((pSession->lastBlkId + 1) < blkNum) {
       int64_t* pIdx = taosArrayGet(pBatchList->pBlkList, pSession->lastBlkId + 1);
       taosRUnLockLatch(&pBatchList->lock);
       code = retrieveBlkFromBufCache(pGCache, pSession->pGroupData, sessionId, *pIdx, &pSession->nextOffset, ppRes);