fix a memory leak for super table join.

src/system/detail/src/vnodeQueryProcess.c

@@ -574,9 +574,9 @@ static void vnodeMultiMeterMultiOutputProcessor(SQInfo *pQInfo) {
 
   SMeterObj *pOneMeter = getMeterObj(pSupporter->pMeterObj, pMeterSidExtInfo[0]->sid);
   
+  if (isPointInterpoQuery(pQuery)) {
     resetCtxOutputBuf(pRuntimeEnv);
   
-  if (isPointInterpoQuery(pQuery)) {
     assert(pQuery->limit.offset == 0 && pQuery->limit.limit != 0);
 
     while (pSupporter->subgroupIdx < pSids->numOfSubSet) {
@@ -664,6 +664,8 @@ static void vnodeMultiMeterMultiOutputProcessor(SQInfo *pQInfo) {
       return;
     }
   
+    resetCtxOutputBuf(pRuntimeEnv);
+  
     for (int32_t i = 0; i < pRuntimeEnv->usedIndex; ++i) {
       SOutputRes *pOneRes = &pRuntimeEnv->pResult[i];
       clearGroupResultBuf(pOneRes, pQuery->numOfOutputCols);