Merge branch 'enh/tsdb_optimize' of https://github.com/taosdata/TDengine into enh/tsdb_optimize

source/dnode/vnode/src/tsdb/tsdbMergeTree.c

@@ -355,7 +355,9 @@ int32_t tLDataIterOpen2(struct SLDataIter *pIter, SSttFileReader *pReader, int32
   return code;
 }
 
-void tLDataIterClose(SLDataIter *pIter) { /*taosMemoryFree(pIter); */}
+void tLDataIterClose2(SLDataIter *pIter) {
+  tsdbSttFileReaderClose(&pIter->pReader);
+}
 
 void tLDataIterNextBlock(SLDataIter *pIter, const char *idStr) {
   int32_t step = pIter->backward ? -1 : 1;

source/dnode/vnode/src/tsdb/tsdbRead2.c

@@ -4746,6 +4746,7 @@ void tsdbReaderClose2(STsdbReader* pReader) {
   if (pReader->status.pTableMap != NULL) {
     destroyAllBlockScanInfo(pReader->status.pTableMap);
     clearBlockScanInfoBuf(&pReader->blockInfoBuf);
+    pReader->status.pTableMap = NULL;
   }
 
   if (pReader->pFileReader != NULL) {