diff --git a/include/libs/function/function.h b/include/libs/function/function.h
index 32b8cc7389b96e7479697b2c864e98543d92e9a1..0ef094b92ee46a3b02e476df34e36f64b94eb7e3 100644
--- a/include/libs/function/function.h
+++ b/include/libs/function/function.h
@@ -136,11 +136,11 @@ typedef struct SqlFunctionCtx {
   uint8_t              scanFlag;    // record current running step, default: 0
   int16_t              functionId;  // function id
   char                *pOutput;     // final result output buffer, point to sdata->data
-  int32_t              numOfParams;
   // input parameter, e.g., top(k, 20), the number of results of top query is kept in param
   SFunctParam         *param;
   // corresponding output buffer for timestamp of each result, e.g., diff/csum
   SColumnInfoData     *pTsOutput;
+  int32_t              numOfParams;
   int32_t              offset;
   SResultRowEntryInfo *resultInfo;
   SSubsidiaryResInfo   subsidiaries;
@@ -152,7 +152,7 @@ typedef struct SqlFunctionCtx {
   struct SSDataBlock  *pSrcBlock;
   struct SSDataBlock  *pDstBlock;  // used by indefinite rows function to set selectivity
   SSerializeDataHandle saveHandle;
-  char                 udfName[TSDB_FUNC_NAME_LEN];
+  char                *udfName;
 } SqlFunctionCtx;
 
 typedef struct tExprNode {
diff --git a/source/libs/executor/src/executil.c b/source/libs/executor/src/executil.c
index fc3cfbd0f65bc7668679fc23aa8466a11ee9ac81..cad6c33f17ee200893513629989e6c84afe3250a 100644
--- a/source/libs/executor/src/executil.c
+++ b/source/libs/executor/src/executil.c
@@ -1513,7 +1513,7 @@ SqlFunctionCtx* createSqlFunctionCtx(SExprInfo* pExprInfo, int32_t numOfOutput,
           fmGetFuncExecFuncs(pCtx->functionId, &pCtx->fpSet);
         } else {
           char* udfName = pExpr->pExpr->_function.pFunctNode->functionName;
-          tstrncpy(pCtx->udfName, udfName, TSDB_FUNC_NAME_LEN);
+          pCtx->udfName = strdup(udfName);
           fmGetUdafExecFuncs(pCtx->functionId, &pCtx->fpSet);
         }
         pCtx->fpSet.getEnv(pExpr->pExpr->_function.pFunctNode, &env);
diff --git a/source/libs/executor/src/executorimpl.c b/source/libs/executor/src/executorimpl.c
index f43ad99966a629c996d1ba5557ed879bf2f3a4f7..2c192bb9bba5c19ae55e84ceb806c6ac29480b2b 100644
--- a/source/libs/executor/src/executorimpl.c
+++ b/source/libs/executor/src/executorimpl.c
@@ -1785,6 +1785,10 @@ void* destroySqlFunctionCtx(SqlFunctionCtx* pCtx, int32_t numOfOutput) {
     taosMemoryFreeClear(pCtx[i].subsidiaries.buf);
     taosMemoryFree(pCtx[i].input.pData);
     taosMemoryFree(pCtx[i].input.pColumnDataAgg);
+
+    if (pCtx[i].udfName != NULL) {
+      taosMemoryFree(pCtx[i].udfName);
+    }
   }
 
   taosMemoryFreeClear(pCtx);
diff --git a/source/util/src/tpagedbuf.c b/source/util/src/tpagedbuf.c
index 7e7712ec8ce41fd5884336dded7d3b4ae9a0c453..984474ceaa008f61bb0e68c32f729eb401a54f18 100644
--- a/source/util/src/tpagedbuf.c
+++ b/source/util/src/tpagedbuf.c
@@ -360,16 +360,13 @@ int32_t createDiskbasedBuf(SDiskbasedBuf** pBuf, int32_t pagesize, int32_t inMem
   // init id hash table
   _hash_fn_t fn = taosGetDefaultHashFunction(TSDB_DATA_TYPE_INT);
   pPBuf->pIdList = taosArrayInit(4, POINTER_BYTES);
-
-  pPBuf->assistBuf = taosMemoryMalloc(pPBuf->pageSize + 2);  // EXTRA BYTES
   pPBuf->all = taosHashInit(10, fn, true, false);
   pPBuf->prefix = (char*) dir;
 
   pPBuf->emptyDummyIdList = taosArrayInit(1, sizeof(int32_t));
 
   //  qDebug("QInfo:0x%"PRIx64" create resBuf for output, page size:%d, inmem buf pages:%d, file:%s", qId,
-  //  pPBuf->pageSize,
-  //         pPBuf->inMemPages, pPBuf->path);
+  //  pPBuf->pageSize, pPBuf->inMemPages, pPBuf->path);
 
   return TSDB_CODE_SUCCESS;
 }
@@ -593,7 +590,12 @@ void setBufPageDirty(void* pPage, bool dirty) {
   ppi->dirty = dirty;
 }
 
-void setBufPageCompressOnDisk(SDiskbasedBuf* pBuf, bool comp) { pBuf->comp = comp; }
+void setBufPageCompressOnDisk(SDiskbasedBuf* pBuf, bool comp) {
+  pBuf->comp = comp;
+  if (comp  && (pBuf->assistBuf == NULL)) {
+    pBuf->assistBuf = taosMemoryMalloc(pBuf->pageSize + 2);  // EXTRA BYTES
+  }
+}
 
 void dBufSetBufPageRecycled(SDiskbasedBuf* pBuf, void* pPage) {
   SPageInfo* ppi = getPageInfoFromPayload(pPage);