From fd79fcc481580fc0c664e3eb7eb379b22af6151c Mon Sep 17 00:00:00 2001
From: shenglian zhou <slzhou@taosdata.com>
Date: Wed, 22 Jun 2022 22:32:29 +0800
Subject: [PATCH] feat: add multiple group tsdb reads to table merge scan

---
 source/libs/executor/src/scanoperator.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/source/libs/executor/src/scanoperator.c b/source/libs/executor/src/scanoperator.c
index a416df4546..13a6a8855c 100644
--- a/source/libs/executor/src/scanoperator.c
+++ b/source/libs/executor/src/scanoperator.c
@@ -2323,7 +2323,11 @@ SSDataBlock* doTableMergeScan(SOperatorInfo* pOperator) {
   size_t tableListSize = taosArrayGetSize(pInfo->tableListInfo->pTableList);
   if (!pInfo->hasGroupId) {
     pInfo->hasGroupId = true;
-
+    
+    if (tableListSize == 0) {
+      doSetOperatorCompleted(pOperator);
+      return NULL;
+    }
     pInfo->tableStartIndex = 0;
     pInfo->groupId = ((STableKeyInfo*)taosArrayGet(pInfo->tableListInfo->pTableList, pInfo->tableStartIndex))->groupId;
     startGroupTableMergeScan(pOperator);