diff --git a/source/dnode/vnode/src/tsdb/tsdbCache.c b/source/dnode/vnode/src/tsdb/tsdbCache.c
index 8fd0d479697..86d87de8cea 100644
--- a/source/dnode/vnode/src/tsdb/tsdbCache.c
+++ b/source/dnode/vnode/src/tsdb/tsdbCache.c
@@ -795,6 +795,9 @@ static int32_t reallocVarDataVal(SValue *pValue) {
     uint8_t *pVal = pValue->pData;
     uint32_t nData = pValue->nData;
     if (nData > 0) {
+      // [TODO]
+      tsdbInfo("reallocVarDataVal(): nData alloced %u", nData);
+      
       uint8_t *p = taosMemoryMalloc(nData);
       if (!p) {
         TAOS_RETURN(terrno);
diff --git a/source/dnode/vnode/src/tsdb/tsdbCacheRead.c b/source/dnode/vnode/src/tsdb/tsdbCacheRead.c
index f28e05c0cb7..a57e9a00fd6 100644
--- a/source/dnode/vnode/src/tsdb/tsdbCacheRead.c
+++ b/source/dnode/vnode/src/tsdb/tsdbCacheRead.c
@@ -164,8 +164,10 @@ static int32_t saveOneRow(SArray* pRow, SSDataBlock* pBlock, SCacheRowsReader* p
           int32_t pkBufLen = (pReader->rowKey.numOfPKs > 0) ? pReader->pkColumn.bytes : 0;
           uint32_t allocBufLen = pReader->pSchema->columns[slotId].bytes + pkBufLen;
           if (allocBufLen < pColVal->colVal.value.nData) {
-            tsdbError("buffer overflow at row key:%" PRIu64 ", data length %u exceeded the allocated buffer size %u",
-                      ts, pColVal->colVal.value.nData, allocBufLen);
+            tsdbError("buffer overflow at row key:%" PRIu64 
+                      ", data length %u exceeded the allocated buffer size %u"
+                      ", pkBufLen = %d",
+                      ts, pColVal->colVal.value.nData, allocBufLen, pkBufLen);
             code = TSDB_CODE_OUT_OF_RANGE;
             TSDB_CHECK_CODE(code, lino, _end);
           }
diff --git a/source/dnode/vnode/src/tsdb/tsdbUtil.c b/source/dnode/vnode/src/tsdb/tsdbUtil.c
index f807ecf2d6c..f8c020e2e7b 100644
--- a/source/dnode/vnode/src/tsdb/tsdbUtil.c
+++ b/source/dnode/vnode/src/tsdb/tsdbUtil.c
@@ -817,6 +817,11 @@ int32_t tsdbRowMergerAdd(SRowMerger *pMerger, TSDBROW *pRow, STSchema *pTSchema)
               code = tRealloc(&pTColVal->value.pData, pColVal->value.nData);
               if (code) return code;
 
+              // [TODO]
+              if (pTColVal->value.nData < pColVal->value.nData) {
+                tsdbInfo("tsdbRowMergedAdd(1): nData changed from %u to %u", pTColVal->value.nData, pColVal->value.nData);
+              }
+
               pTColVal->value.nData = pColVal->value.nData;
               if (pTColVal->value.nData) {
                 memcpy(pTColVal->value.pData, pColVal->value.pData, pTColVal->value.nData);
@@ -837,6 +842,11 @@ int32_t tsdbRowMergerAdd(SRowMerger *pMerger, TSDBROW *pRow, STSchema *pTSchema)
             code = tRealloc(&tColVal->value.pData, pColVal->value.nData);
             if (code) return code;
 
+            // [TODO]
+            if (tColVal->value.nData < pColVal->value.nData) {
+              tsdbInfo("tsdbRowMergedAdd(-1): nData changed from %u to %u", tColVal->value.nData, pColVal->value.nData);
+            }
+
             tColVal->value.nData = pColVal->value.nData;
             if (pColVal->value.nData) {
               memcpy(tColVal->value.pData, pColVal->value.pData, pColVal->value.nData);