diff --git a/source/libs/function/src/builtins.c b/source/libs/function/src/builtins.c
index b22a9866c3fc612a603595f7da8812cfa5c37ed0..900fd749f5d598b4f10dfa3acf8638f62e05b6bd 100644
--- a/source/libs/function/src/builtins.c
+++ b/source/libs/function/src/builtins.c
@@ -266,6 +266,20 @@ static int32_t translateFirstLast(SFunctionNode* pFunc, char* pErrBuf, int32_t l
   return TSDB_CODE_SUCCESS;
 }
 
+static int32_t translateDiff(SFunctionNode* pFunc, char* pErrBuf, int32_t len) {
+  int32_t paraLen = LIST_LENGTH(pFunc->pParameterList);
+  if (paraLen == 0 || paraLen > 2) {
+    return invaildFuncParaNumErrMsg(pErrBuf, len, pFunc->functionName);
+  }
+
+  SExprNode* p1 = (SExprNode*)nodesListGetNode(pFunc->pParameterList, 0);
+  if (!IS_NUMERIC_TYPE(p1->resType.type)) {
+    return invaildFuncParaTypeErrMsg(pErrBuf, len, pFunc->functionName);
+  }
+  pFunc->node.resType = p1->resType;
+  return TSDB_CODE_SUCCESS;
+}
+
 static int32_t translateLength(SFunctionNode* pFunc, char* pErrBuf, int32_t len) {
   if (1 != LIST_LENGTH(pFunc->pParameterList)) {
     return invaildFuncParaNumErrMsg(pErrBuf, len, pFunc->functionName);
@@ -613,7 +627,7 @@ const SBuiltinFuncDefinition funcMgtBuiltins[] = {
     .name = "diff",
     .type = FUNCTION_TYPE_DIFF,
     .classification = FUNC_MGT_NONSTANDARD_SQL_FUNC | FUNC_MGT_TIMELINE_FUNC,
-    .translateFunc = translateInOutNum,
+    .translateFunc = translateDiff,
     .getEnvFunc   = getDiffFuncEnv,
     .initFunc     = diffFunctionSetup,
     .processFunc  = diffFunction,
diff --git a/source/libs/function/src/builtinsimpl.c b/source/libs/function/src/builtinsimpl.c
index 896c1c9164f464efe078caf12854e7770927936a..f5d6521ef4070c4e81e9987b8148923f4f3e8c60 100644
--- a/source/libs/function/src/builtinsimpl.c
+++ b/source/libs/function/src/builtinsimpl.c
@@ -75,7 +75,7 @@ typedef struct SPercentileInfo {
 typedef struct SDiffInfo {
   bool hasPrev;
   bool includeNull;
-  bool ignoreNegative;
+  bool ignoreNegative;  // replace the ignore with case when
   bool firstOutput;
   union {
     int64_t i64;
@@ -1208,248 +1208,192 @@ bool diffFunctionSetup(SqlFunctionCtx* pCtx, SResultRowEntryInfo* pResInfo) {
   SDiffInfo* pDiffInfo = GET_ROWCELL_INTERBUF(pResInfo);
   pDiffInfo->hasPrev = false;
   pDiffInfo->prev.i64 = 0;
-  pDiffInfo->ignoreNegative = false;  // TODO set correct param
+  pDiffInfo->ignoreNegative = pCtx->param[1].param.i;  // TODO set correct param
   pDiffInfo->includeNull = false;
   pDiffInfo->firstOutput = false;
   return true;
 }
 
+static void doSetPrevVal(SDiffInfo* pDiffInfo, int32_t type, const char* pv) {
+  switch(type) {
+    case TSDB_DATA_TYPE_BOOL:
+    case TSDB_DATA_TYPE_TINYINT:
+      pDiffInfo->prev.i64 = *(int8_t*) pv; break;
+    case TSDB_DATA_TYPE_INT:
+      pDiffInfo->prev.i64 = *(int32_t*) pv; break;
+    case TSDB_DATA_TYPE_SMALLINT:
+      pDiffInfo->prev.i64 = *(int16_t*) pv; break;
+    case TSDB_DATA_TYPE_BIGINT:
+      pDiffInfo->prev.i64 = *(int64_t*) pv; break;
+    case TSDB_DATA_TYPE_FLOAT:
+      pDiffInfo->prev.d64 = *(float *) pv; break;
+    case TSDB_DATA_TYPE_DOUBLE:
+      pDiffInfo->prev.d64 = *(double*) pv; break;
+    default:
+      ASSERT(0);
+  }
+}
+
+static void doHandleDiff(SDiffInfo* pDiffInfo, int32_t type, const char* pv, SColumnInfoData* pOutput, int32_t pos, int32_t order) {
+    int32_t factor = (order == TSDB_ORDER_ASC)? 1:-1;
+  switch (type) {
+    case TSDB_DATA_TYPE_INT: {
+      int32_t v = *(int32_t*)pv;
+      int32_t delta = factor*(v - pDiffInfo->prev.i64);  // direct previous may be null
+      if (delta < 0 && pDiffInfo->ignoreNegative) {
+        colDataSetNull_f(pOutput->nullbitmap, pos);
+      } else {
+        colDataAppendInt32(pOutput, pos, &delta);
+      }
+      pDiffInfo->prev.i64 = v;
+      break;
+    }
+    case TSDB_DATA_TYPE_BOOL:
+    case TSDB_DATA_TYPE_TINYINT: {
+      int8_t v = *(int8_t*)pv;
+      int8_t delta = factor*(v - pDiffInfo->prev.i64);  // direct previous may be null
+      if (delta < 0 && pDiffInfo->ignoreNegative) {
+        colDataSetNull_f(pOutput->nullbitmap, pos);
+      } else {
+        colDataAppendInt8(pOutput, pos, &delta);
+      }
+      pDiffInfo->prev.i64 = v;
+      break;
+    }
+    case TSDB_DATA_TYPE_SMALLINT: {
+      int16_t v = *(int16_t*)pv;
+      int16_t delta = factor*(v - pDiffInfo->prev.i64);  // direct previous may be null
+      if (delta < 0 && pDiffInfo->ignoreNegative) {
+        colDataSetNull_f(pOutput->nullbitmap, pos);
+      } else {
+        colDataAppendInt16(pOutput, pos, &delta);
+      }
+      pDiffInfo->prev.i64 = v;
+      break;
+    }
+    case TSDB_DATA_TYPE_BIGINT: {
+      int64_t v = *(int64_t*)pv;
+      int64_t delta = factor*(v - pDiffInfo->prev.i64);  // direct previous may be null
+      if (delta < 0 && pDiffInfo->ignoreNegative) {
+        colDataSetNull_f(pOutput->nullbitmap, pos);
+      } else {
+        colDataAppendInt64(pOutput, pos, &delta);
+      }
+      pDiffInfo->prev.i64 = v;
+      break;
+    }
+    case TSDB_DATA_TYPE_FLOAT: {
+      float v = *(float*)pv;
+      float delta = factor*(v - pDiffInfo->prev.d64);  // direct previous may be null
+      if (delta < 0 && pDiffInfo->ignoreNegative) {
+        colDataSetNull_f(pOutput->nullbitmap, pos);
+      } else {
+        colDataAppendFloat(pOutput, pos, &delta);
+      }
+      pDiffInfo->prev.d64 = v;
+      break;
+    }
+    case TSDB_DATA_TYPE_DOUBLE: {
+      double v = *(double*)pv;
+      double delta = factor*(v - pDiffInfo->prev.d64);  // direct previous may be null
+      if (delta < 0 && pDiffInfo->ignoreNegative) {
+        colDataSetNull_f(pOutput->nullbitmap, pos);
+      } else {
+        colDataAppendDouble(pOutput, pos, &delta);
+      }
+      pDiffInfo->prev.d64 = v;
+      break;
+    }
+    default:
+      ASSERT(0);
+  }
+  }
+
 int32_t diffFunction(SqlFunctionCtx* pCtx) {
   SResultRowEntryInfo* pResInfo = GET_RES_INFO(pCtx);
   SDiffInfo*           pDiffInfo = GET_ROWCELL_INTERBUF(pResInfo);
 
   SInputColumnInfoData* pInput = &pCtx->input;
-  SColumnInfoData*      pInputCol = pInput->pData[0];
-
-  bool    isFirstBlock = (pDiffInfo->hasPrev == false);
-  int32_t numOfElems = 0;
 
+  SColumnInfoData* pInputCol = pInput->pData[0];
   SColumnInfoData* pTsOutput = pCtx->pTsOutput;
-  TSKEY*           tsList = (int64_t*)pInput->pPTS->pData;
 
+  int32_t numOfElems = 0;
+  TSKEY* tsList = (int64_t*)pInput->pPTS->pData;
   int32_t startOffset = pCtx->offset;
-  switch (pInputCol->info.type) {
-    case TSDB_DATA_TYPE_INT: {
-      SColumnInfoData* pOutput = (SColumnInfoData*)pCtx->pOutput;
-      if (pCtx->order == TSDB_ORDER_ASC) {
-        for (int32_t i = pInput->startRowIndex; i < pInput->numOfRows + pInput->startRowIndex; i += 1) {
-          int32_t pos = startOffset + (isFirstBlock ? (numOfElems - 1) : numOfElems);
-          if (colDataIsNull_f(pInputCol->nullbitmap, i)) {
-            if (pDiffInfo->includeNull) {
-              colDataSetNull_f(pOutput->nullbitmap, pos);
-              if (tsList != NULL) {
-                colDataAppendInt64(pTsOutput, pos, &tsList[i]);
-              }
-
-              numOfElems += 1;
-            }
-            continue;
-          }
 
-          int32_t v = *(int32_t*)colDataGetData(pInputCol, i);
-          if (pDiffInfo->hasPrev) {
-            int32_t delta = (int32_t)(v - pDiffInfo->prev.i64);  // direct previous may be null
-            if (delta < 0 && pDiffInfo->ignoreNegative) {
-              colDataSetNull_f(pOutput->nullbitmap, pos);
-            } else {
-              colDataAppendInt32(pOutput, pos, &delta);
-            }
-
-            if (pTsOutput != NULL) {
-              colDataAppendInt64(pTsOutput, pos, &tsList[i]);
-            }
-          }
+  SColumnInfoData* pOutput = (SColumnInfoData*)pCtx->pOutput;
 
-          pDiffInfo->prev.i64 = v;
-          pDiffInfo->hasPrev = true;
-          numOfElems++;
-        }
-      } else {
-        for (int32_t i = pInput->startRowIndex; i < pInput->numOfRows + pInput->startRowIndex; i += 1) {
-          int32_t v = *(int32_t*)colDataGetData(pInputCol, i);
-          int32_t pos = startOffset + numOfElems;
-
-          // there is a row of previous data block to be handled in the first place.
-          if (pDiffInfo->hasPrev) {
-            int32_t delta = (int32_t)(pDiffInfo->prev.i64 - v);  // direct previous may be null
-            if (delta < 0 && pDiffInfo->ignoreNegative) {
-              colDataSetNull_f(pOutput->nullbitmap, pos);
-            } else {
-              colDataAppendInt32(pOutput, pos, &delta);
-            }
+  if (pCtx->order == TSDB_ORDER_ASC) {
+    for (int32_t i = pInput->startRowIndex; i < pInput->numOfRows + pInput->startRowIndex; i += 1) {
+      int32_t pos = startOffset + numOfElems;
 
-            if (pTsOutput != NULL) {
-              colDataAppendInt64(pTsOutput, pos, &pDiffInfo->prevTs);
-            }
-            pDiffInfo->hasPrev = false;
+      if (colDataIsNull_f(pInputCol->nullbitmap, i)) {
+        if (pDiffInfo->includeNull) {
+          colDataSetNull_f(pOutput->nullbitmap, pos);
+          if (tsList != NULL) {
+            colDataAppendInt64(pTsOutput, pos, &tsList[i]);
           }
 
-          // it is not the last row of current block
-          if (i < pInput->numOfRows + pInput->startRowIndex - 1) {
-            int32_t next = *(int32_t*)colDataGetData(pInputCol, i + 1);
-
-            int32_t delta = v - next;  // direct previous may be null
-            colDataAppendInt32(pOutput, pos, &delta);
-
-            if (pTsOutput != NULL) {
-              colDataAppendInt64(pTsOutput, pos, &tsList[i]);
-            }
-          } else {
-            pDiffInfo->prev.i64 = v;
-            if (pTsOutput != NULL) {
-              pDiffInfo->prevTs = tsList[i];
-            }
-            pDiffInfo->hasPrev = true;
-          }
-          numOfElems++;
+          numOfElems += 1;
         }
-
+        continue;
       }
-      break;
-    }
 
-    case TSDB_DATA_TYPE_BIGINT: {
-      SColumnInfoData* pOutput = (SColumnInfoData*)pCtx->pOutput;
-      for (int32_t i = pInput->startRowIndex; i < pInput->numOfRows + pInput->startRowIndex; i += 1) {
-        if (colDataIsNull_f(pInputCol->nullbitmap, i)) {
-          continue;
-        }
-
-        int32_t v = 0;
-        if (pDiffInfo->hasPrev) {
-          v = *(int64_t*)colDataGetData(pInputCol, i);
-          int64_t delta = (int64_t)(v - pDiffInfo->prev.i64);  // direct previous may be null
-          if (pDiffInfo->ignoreNegative) {
-            continue;
-          }
+      char* pv = colDataGetData(pInputCol, i);
 
-          //          *(pOutput++) = delta;
-          //          *pTimestamp  = (tsList != NULL)? tsList[i]:0;
-          //
-          //          pOutput    += 1;
-          //          pTimestamp += 1;
+      if (pDiffInfo->hasPrev) {
+        doHandleDiff(pDiffInfo, pInputCol->info.type, pv, pOutput, pos, pCtx->order);
+        if (pTsOutput != NULL) {
+          colDataAppendInt64(pTsOutput, pos, &tsList[i]);
         }
 
-        pDiffInfo->prev.i64 = v;
-        pDiffInfo->hasPrev = true;
         numOfElems++;
+      } else {
+        doSetPrevVal(pDiffInfo, pInputCol->info.type, pv);
       }
-      break;
-    }
-#if 0
-    case TSDB_DATA_TYPE_DOUBLE: {
-      double *pData = (double *)data;
-      double *pOutput = (double *)pCtx->pOutput;
 
-      for (; i < pCtx->size && i >= 0; i += step) {
-        if (pCtx->hasNull && isNull((const char*) &pData[i], pCtx->inputType)) {
-          continue;
-        }
-        if ((pDiffInfo->ignoreNegative) && (pData[i] < 0)) {
-          continue;
-        }
-
-        if (pDiffInfo->hasPrev) {  // initial value is not set yet
-          SET_DOUBLE_VAL(pOutput, pData[i] - pDiffInfo->d64Prev);  // direct previous may be null
-          *pTimestamp = (tsList != NULL)? tsList[i]:0;
-          pOutput    += 1;
-          pTimestamp += 1;
-        }
-
-        pDiffInfo->d64Prev = pData[i];
-        pDiffInfo->hasPrev = true;
-        numOfElems++;
-      }
-      break;
+      pDiffInfo->hasPrev = true;
     }
-    case TSDB_DATA_TYPE_FLOAT: {
-      float *pData = (float *)data;
-      float *pOutput = (float *)pCtx->pOutput;
-
-      for (; i < pCtx->size && i >= 0; i += step) {
-        if (pCtx->hasNull && isNull((const char*) &pData[i], pCtx->inputType)) {
-          continue;
-        }
-        if ((pDiffInfo->ignoreNegative) && (pData[i] < 0)) {
-          continue;
-        }
+  } else {
+    for (int32_t i = pInput->startRowIndex; i < pInput->numOfRows + pInput->startRowIndex; i += 1) {
+      int32_t pos = startOffset + numOfElems;
+
+      if (colDataIsNull_f(pInputCol->nullbitmap, i)) {
+        if (pDiffInfo->includeNull) {
+          colDataSetNull_f(pOutput->nullbitmap, pos);
+          if (tsList != NULL) {
+            colDataAppendInt64(pTsOutput, pos, &tsList[i]);
+          }
 
-        if (pDiffInfo->hasPrev) {  // initial value is not set yet
-          *pOutput = (float)(pData[i] - pDiffInfo->d64Prev);  // direct previous may be null
-          *pTimestamp = (tsList != NULL)? tsList[i]:0;
-          pOutput    += 1;
-          pTimestamp += 1;
+          numOfElems += 1;
         }
-
-        pDiffInfo->d64Prev = pData[i];
-        pDiffInfo->hasPrev = true;
-        numOfElems++;
+        continue;
       }
-      break;
-    }
-    case TSDB_DATA_TYPE_SMALLINT: {
-      int16_t *pData = (int16_t *)data;
-      int16_t *pOutput = (int16_t *)pCtx->pOutput;
 
-      for (; i < pCtx->size && i >= 0; i += step) {
-        if (pCtx->hasNull && isNull((const char*) &pData[i], pCtx->inputType)) {
-          continue;
-        }
-        if ((pDiffInfo->ignoreNegative) && (pData[i] < 0)) {
-          continue;
-        }
+      char* pv = colDataGetData(pInputCol, i);
 
-        if (pDiffInfo->hasPrev) {  // initial value is not set yet
-          *pOutput = (int16_t)(pData[i] - pDiffInfo->i64Prev);  // direct previous may be null
-          *pTimestamp = (tsList != NULL)? tsList[i]:0;
-          pOutput    += 1;
-          pTimestamp += 1;
+      // there is a row of previous data block to be handled in the first place.
+      if (pDiffInfo->hasPrev) {
+        doHandleDiff(pDiffInfo, pInputCol->info.type, pv, pOutput, pos, pCtx->order);
+        if (pTsOutput != NULL) {
+          colDataAppendInt64(pTsOutput, pos, &pDiffInfo->prevTs);
         }
 
-        pDiffInfo->i64Prev = pData[i];
-        pDiffInfo->hasPrev = true;
         numOfElems++;
+      } else {
+        doSetPrevVal(pDiffInfo, pInputCol->info.type, pv);
       }
-      break;
-    }
-
-    case TSDB_DATA_TYPE_TINYINT: {
-      int8_t *pData = (int8_t *)data;
-      int8_t *pOutput = (int8_t *)pCtx->pOutput;
 
-      for (; i < pCtx->size && i >= 0; i += step) {
-        if (pCtx->hasNull && isNull((char *)&pData[i], pCtx->inputType)) {
-          continue;
-        }
-        if ((pDiffInfo->ignoreNegative) && (pData[i] < 0)) {
-          continue;
-        }
-
-        if (pDiffInfo->hasPrev) {  // initial value is not set yet
-          *pOutput = (int8_t)(pData[i] - pDiffInfo->i64Prev);  // direct previous may be null
-          *pTimestamp = (tsList != NULL)? tsList[i]:0;
-          pOutput    += 1;
-          pTimestamp += 1;
-        }
-
-        pDiffInfo->i64Prev = pData[i];
-        pDiffInfo->hasPrev = true;
-        numOfElems++;
+      pDiffInfo->hasPrev = true;
+      if (pTsOutput != NULL) {
+        pDiffInfo->prevTs = tsList[i];
       }
-      break;
     }
-#endif
-    default:
-      break;
-      //      qError("error input type");
   }
 
   // initial value is not set yet
-  if (numOfElems <= 0) {
-    return 0;
-  } else {
-    return (isFirstBlock) ? numOfElems - 1 : numOfElems;
-  }
+  return numOfElems;
 }
 
 bool getTopBotFuncEnv(SFunctionNode* pFunc, SFuncExecEnv* pEnv) {