diff --git a/include/util/tarray.h b/include/util/tarray.h
index e95568197b63b8b58e62ecf56783ed3f4dc231ee..0632db310326d826b8393fe873610ec1cf0d8159 100644
--- a/include/util/tarray.h
+++ b/include/util/tarray.h
@@ -104,6 +104,15 @@ static FORCE_INLINE void* taosArrayPush(SArray* pArray, const void* pData) {
   return taosArrayAddBatch(pArray, pData, 1);
 }
 
+/**
+ * @brief reserve the capacity of the array
+ *
+ * @param pArray
+ * @param num
+ * @return void* the start position of the reserved memory
+ */
+void* taosArrayReserve(SArray* pArray, int32_t num);
+
 /**
  *
  * @param pArray
diff --git a/source/dnode/vnode/src/inc/tsdb.h b/source/dnode/vnode/src/inc/tsdb.h
index d335e84c4c4c653e533b3f19b0a174f7eefa0f34..7fb962e3a7b300bde16b89af2dbb14c9e05dc6ad 100644
--- a/source/dnode/vnode/src/inc/tsdb.h
+++ b/source/dnode/vnode/src/inc/tsdb.h
@@ -185,6 +185,8 @@ int32_t tMapDataSearch(SMapData *pMapData, void *pSearchItem, int32_t (*tGetItem
                        int32_t (*tItemCmprFn)(const void *, const void *), void *pItem);
 int32_t tPutMapData(uint8_t *p, SMapData *pMapData);
 int32_t tGetMapData(uint8_t *p, SMapData *pMapData);
+int32_t tMapDataToArray(SMapData *pMapData, int32_t itemSize, int32_t (*tGetItemFn)(uint8_t *, void *),
+                        SArray **ppArray);
 // other
 int32_t tsdbKeyFid(TSKEY key, int32_t minutes, int8_t precision);
 void    tsdbFidKeyRange(int32_t fid, int32_t minutes, int8_t precision, TSKEY *minKey, TSKEY *maxKey);
diff --git a/source/dnode/vnode/src/tsdb/tsdbUtil.c b/source/dnode/vnode/src/tsdb/tsdbUtil.c
index 599428564788afeb1c962965f95c4fc35cde8a4a..db86a9429d255c5a441a81482f5c4d62aac6e338 100644
--- a/source/dnode/vnode/src/tsdb/tsdbUtil.c
+++ b/source/dnode/vnode/src/tsdb/tsdbUtil.c
@@ -101,6 +101,30 @@ void tMapDataGetItemByIdx(SMapData *pMapData, int32_t idx, void *pItem, int32_t
   tGetItemFn(pMapData->pData + pMapData->aOffset[idx], pItem);
 }
 
+int32_t tMapDataToArray(SMapData *pMapData, int32_t itemSize, int32_t (*tGetItemFn)(uint8_t *, void *),
+                        SArray **ppArray) {
+  int32_t code = 0;
+
+  SArray *pArray = taosArrayInit(pMapData->nItem, itemSize);
+  if (pArray == NULL) {
+    code = TSDB_CODE_TDB_OUT_OF_MEMORY;
+    goto _exit;
+  }
+
+  for (int32_t i = 0; i < pMapData->nItem; i++) {
+    tMapDataGetItemByIdx(pMapData, i, taosArrayReserve(pArray, 1), tGetItemFn);
+  }
+
+_exit:
+  if (code) {
+    *ppArray = NULL;
+    if (pArray) taosArrayDestroy(pArray);
+  } else {
+    *ppArray = pArray;
+  }
+  return code;
+}
+
 int32_t tPutMapData(uint8_t *p, SMapData *pMapData) {
   int32_t n = 0;
 
diff --git a/source/util/src/tarray.c b/source/util/src/tarray.c
index 95065972a3a890c253004033b1b33c5b76dd0467..5703d8f8f465486590de5f0337a97fa724741665 100644
--- a/source/util/src/tarray.c
+++ b/source/util/src/tarray.c
@@ -181,6 +181,17 @@ void* taosArrayAddAll(SArray* pArray, const SArray* pInput) {
   }
 }
 
+void* taosArrayReserve(SArray* pArray, int32_t num) {
+  if (taosArrayEnsureCap(pArray, pArray->size + num) != 0) {
+    return NULL;
+  }
+
+  void* dst = TARRAY_GET_ELEM(pArray, pArray->size);
+  pArray->size += num;
+
+  return dst;
+}
+
 void* taosArrayPop(SArray* pArray) {
   assert(pArray != NULL);