diff --git a/docs/en/12-taos-sql/06-select.md b/docs/en/12-taos-sql/06-select.md
index de7294f7a9..070fd41653 100644
--- a/docs/en/12-taos-sql/06-select.md
+++ b/docs/en/12-taos-sql/06-select.md
@@ -55,7 +55,7 @@ window_clause: {
   | INTERVAL(interval_val [, interval_offset]) [SLIDING (sliding_val)] [WATERMARK(watermark_val)] [FILL(fill_mod_and_val)]
 
 interp_clause:
-    RANGE(ts_val, ts_val), EVERY(every_val), FILL(fill_mod_and_val)
+    RANGE(ts_val, ts_val) EVERY(every_val) FILL(fill_mod_and_val)
 
 partition_by_clause:
     PARTITION BY expr [, expr] ...
diff --git a/docs/en/12-taos-sql/10-function.md b/docs/en/12-taos-sql/10-function.md
index 0b5f9103c7..5c0ad8a71d 100644
--- a/docs/en/12-taos-sql/10-function.md
+++ b/docs/en/12-taos-sql/10-function.md
@@ -886,7 +886,7 @@ INTERP(expr)
 - The output time range of `INTERP` is specified by `RANGE(timestamp1,timestamp2)` parameter, with timestamp1 <= timestamp2. timestamp1 is the starting point of the output time range and must be specified. timestamp2 is the ending point of the output time range and must be specified.
 - The number of rows in the result set of `INTERP` is determined by the parameter `EVERY(time_unit)`. Starting from timestamp1, one interpolation is performed for every time interval specified `time_unit` parameter. The parameter `time_unit` must be an integer, with no quotes, with a time unit of: a(millisecond)), s(second), m(minute), h(hour), d(day), or w(week). For example, `EVERY(500a)` will interpolate every 500 milliseconds.
 - Interpolation is performed based on `FILL` parameter. For more information about FILL clause, see [FILL Clause](../distinguished/#fill-clause).
-- `INTERP` can only be used to interpolate in single timeline. So it must be used with `partition by tbname` when it's used on a STable.
+- `INTERP` can be applied to supertable by interpolating primary key sorted data of all its childtables. It can also be used with `partition by tbname` when applied to supertable to generate interpolation on each single timeline.
 - Pseudocolumn `_irowts` can be used along with `INTERP` to return the timestamps associated with interpolation points(support after version 3.0.2.0).
 - Pseudocolumn `_isfilled` can be used along with `INTERP` to indicate whether the results are original records or data points generated by interpolation algorithm(support after version 3.0.3.0).
 
diff --git a/docs/zh/12-taos-sql/06-select.md b/docs/zh/12-taos-sql/06-select.md
index e4ba5b76e4..870df73471 100644
--- a/docs/zh/12-taos-sql/06-select.md
+++ b/docs/zh/12-taos-sql/06-select.md
@@ -55,7 +55,7 @@ window_clause: {
   | INTERVAL(interval_val [, interval_offset]) [SLIDING (sliding_val)] [WATERMARK(watermark_val)] [FILL(fill_mod_and_val)]
 
 interp_clause:
-    RANGE(ts_val, ts_val), EVERY(every_val), FILL(fill_mod_and_val)
+    RANGE(ts_val, ts_val) EVERY(every_val) FILL(fill_mod_and_val)
 
 partition_by_clause:
     PARTITION BY expr [, expr] ...
diff --git a/docs/zh/12-taos-sql/10-function.md b/docs/zh/12-taos-sql/10-function.md
index 50e82e6b90..458fc9c7a2 100644
--- a/docs/zh/12-taos-sql/10-function.md
+++ b/docs/zh/12-taos-sql/10-function.md
@@ -888,7 +888,7 @@ INTERP(expr)
 - INTERP 的输出时间范围根据 RANGE(timestamp1,timestamp2)字段来指定，需满足 timestamp1 <= timestamp2。其中 timestamp1（必选值）为输出时间范围的起始值，即如果 timestamp1 时刻符合插值条件则 timestamp1 为输出的第一条记录，timestamp2（必选值）为输出时间范围的结束值，即输出的最后一条记录的 timestamp 不能大于 timestamp2。
 - INTERP 根据 EVERY(time_unit) 字段来确定输出时间范围内的结果条数，即从 timestamp1 开始每隔固定长度的时间（time_unit 值）进行插值，time_unit 可取值时间单位：1a(毫秒)，1s(秒)，1m(分)，1h(小时)，1d(天)，1w(周)。例如 EVERY(500a) 将对于指定数据每500毫秒间隔进行一次插值.
 - INTERP 根据 FILL 字段来决定在每个符合输出条件的时刻如何进行插值。关于 FILL 子句如何使用请参考 [FILL 子句](../distinguished/#fill-子句)
-- INTERP 只能在一个时间序列内进行插值，因此当作用于超级表时必须跟 partition by tbname 一起使用。
+- INTERP 作用于超级表时, 会将该超级表下的所有子表数据按照主键列排序后进行插值计算，也可以搭配 PARTITION BY tbname 使用，将结果强制规约到单个时间线。
 - INTERP 可以与伪列 _irowts 一起使用，返回插值点所对应的时间戳(3.0.2.0版本以后支持)。
 - INTERP 可以与伪列 _isfilled 一起使用，显示返回结果是否为原始记录或插值算法产生的数据(3.0.3.0版本以后支持)。
 
diff --git a/source/libs/executor/src/timesliceoperator.c b/source/libs/executor/src/timesliceoperator.c
index f0e25d8cc5..b7f7a44080 100644
--- a/source/libs/executor/src/timesliceoperator.c
+++ b/source/libs/executor/src/timesliceoperator.c
@@ -36,6 +36,11 @@ typedef struct STimeSliceOperatorInfo {
   SColumn              tsCol;         // primary timestamp column
   SExprSupp            scalarSup;     // scalar calculation
   struct SFillColInfo* pFillColInfo;  // fill column info
+  int64_t              prevTs;
+  bool                 prevTsSet;
+  uint64_t             groupId;
+  SGroupKeys*          pPrevGroupKey;
+  SSDataBlock*         pNextGroupRes;
 } STimeSliceOperatorInfo;
 
 static void destroyTimeSliceOperatorInfo(void* param);
@@ -166,18 +171,55 @@ static bool isIsfilledPseudoColumn(SExprInfo* pExprInfo) {
   return (IS_BOOLEAN_TYPE(pExprInfo->base.resSchema.type) && strcasecmp(name, "_isfilled") == 0);
 }
 
+static bool checkDuplicateTimestamps(STimeSliceOperatorInfo* pSliceInfo, SColumnInfoData* pTsCol,
+                                     int32_t curIndex, int32_t rows) {
+
+
+  int64_t currentTs = *(int64_t*)colDataGetData(pTsCol, curIndex);
+  if (currentTs > pSliceInfo->win.ekey) {
+    return false;
+  }
+
+  if ((pSliceInfo->prevTsSet == true) && (currentTs == pSliceInfo->prevTs)) {
+    return true;
+  }
+
+  pSliceInfo->prevTsSet = true;
+  pSliceInfo->prevTs = currentTs;
+
+  if (currentTs == pSliceInfo->win.ekey && curIndex < rows - 1) {
+    int64_t nextTs = *(int64_t*)colDataGetData(pTsCol, curIndex + 1);
+    if (currentTs == nextTs) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
+static bool isInterpFunc(SExprInfo* pExprInfo) {
+  int32_t functionType = pExprInfo->pExpr->_function.functionType;
+  return (functionType == FUNCTION_TYPE_INTERP);
+}
+
+static bool isGroupKeyFunc(SExprInfo* pExprInfo) {
+  int32_t functionType = pExprInfo->pExpr->_function.functionType;
+  return (functionType == FUNCTION_TYPE_GROUP_KEY);
+}
+
 static bool genInterpolationResult(STimeSliceOperatorInfo* pSliceInfo, SExprSupp* pExprSup, SSDataBlock* pResBlock,
-                                   bool beforeTs) {
+                                   SSDataBlock* pSrcBlock, int32_t index, bool beforeTs) {
   int32_t rows = pResBlock->info.rows;
   timeSliceEnsureBlockCapacity(pSliceInfo, pResBlock);
   // todo set the correct primary timestamp column
 
+
   // output the result
   bool hasInterp = true;
   for (int32_t j = 0; j < pExprSup->numOfExprs; ++j) {
     SExprInfo* pExprInfo = &pExprSup->pExprInfo[j];
 
-    int32_t          dstSlot = pExprInfo->base.resSchema.slotId;
+    int32_t       dstSlot = pExprInfo->base.resSchema.slotId;
     SColumnInfoData* pDst = taosArrayGet(pResBlock->pDataBlock, dstSlot);
 
     if (isIrowtsPseudoColumn(pExprInfo)) {
@@ -187,6 +229,30 @@ static bool genInterpolationResult(STimeSliceOperatorInfo* pSliceInfo, SExprSupp
       bool isFilled = true;
       colDataAppend(pDst, pResBlock->info.rows, (char*)&isFilled, false);
       continue;
+    } else if (!isInterpFunc(pExprInfo)) {
+      if (isGroupKeyFunc(pExprInfo)) {
+        if (pSrcBlock != NULL) {
+          int32_t       srcSlot = pExprInfo->base.pParam[0].pCol->slotId;
+          SColumnInfoData* pSrc = taosArrayGet(pSrcBlock->pDataBlock, srcSlot);
+
+          if (colDataIsNull_s(pSrc, index)) {
+            colDataSetNULL(pDst, pResBlock->info.rows);
+            continue;
+          }
+
+          char* v = colDataGetData(pSrc, index);
+          colDataSetVal(pDst, pResBlock->info.rows, v, false);
+        } else {
+          // use stored group key
+          SGroupKeys* pkey = pSliceInfo->pPrevGroupKey;
+          if (pkey->isNull == false) {
+            colDataSetVal(pDst, rows, pkey->pData, false);
+          } else {
+            colDataSetNULL(pDst, rows);
+          }
+        }
+      }
+      continue;
     }
 
     int32_t srcSlot = pExprInfo->base.pParam[0].pCol->slotId;
@@ -312,7 +378,7 @@ static void addCurrentRowToResult(STimeSliceOperatorInfo* pSliceInfo, SExprSupp*
       bool isFilled = false;
       colDataSetVal(pDst, pResBlock->info.rows, (char*)&isFilled, false);
     } else {
-      int32_t          srcSlot = pExprInfo->base.pParam[0].pCol->slotId;
+      int32_t       srcSlot = pExprInfo->base.pParam[0].pCol->slotId;
       SColumnInfoData* pSrc = taosArrayGet(pSrcBlock->pDataBlock, srcSlot);
 
       if (colDataIsNull_s(pSrc, index)) {
@@ -412,7 +478,31 @@ static int32_t initFillLinearInfo(STimeSliceOperatorInfo* pInfo, SSDataBlock* pB
   return TSDB_CODE_SUCCESS;
 }
 
-static int32_t initKeeperInfo(STimeSliceOperatorInfo* pInfo, SSDataBlock* pBlock) {
+static int32_t initGroupKeyKeeper(STimeSliceOperatorInfo* pInfo, SExprSupp* pExprSup) {
+  if (pInfo->pPrevGroupKey != NULL) {
+    return TSDB_CODE_SUCCESS;
+  }
+
+  pInfo->pPrevGroupKey = taosMemoryCalloc(1, sizeof(SGroupKeys));
+  if (pInfo->pPrevGroupKey == NULL) {
+    return TSDB_CODE_OUT_OF_MEMORY;
+  }
+
+  for (int32_t i = 0; i < pExprSup->numOfExprs; ++i) {
+    SExprInfo* pExprInfo = &pExprSup->pExprInfo[i];
+
+    if (isGroupKeyFunc(pExprInfo)) {
+      pInfo->pPrevGroupKey->bytes = pExprInfo->base.resSchema.bytes;
+      pInfo->pPrevGroupKey->type = pExprInfo->base.resSchema.type;
+      pInfo->pPrevGroupKey->isNull = false;
+      pInfo->pPrevGroupKey->pData = taosMemoryCalloc(1, pInfo->pPrevGroupKey->bytes);
+    }
+  }
+
+  return TSDB_CODE_SUCCESS;
+}
+
+static int32_t initKeeperInfo(STimeSliceOperatorInfo* pInfo, SSDataBlock* pBlock, SExprSupp* pExprSup) {
   int32_t code;
   code = initPrevRowsKeeper(pInfo, pBlock);
   if (code != TSDB_CODE_SUCCESS) {
@@ -429,9 +519,202 @@ static int32_t initKeeperInfo(STimeSliceOperatorInfo* pInfo, SSDataBlock* pBlock
     return TSDB_CODE_FAILED;
   }
 
+  code = initGroupKeyKeeper(pInfo, pExprSup);
+  if (code != TSDB_CODE_SUCCESS) {
+    return TSDB_CODE_FAILED;
+  }
+
+
   return TSDB_CODE_SUCCESS;
 }
 
+static int32_t resetPrevRowsKeeper(STimeSliceOperatorInfo* pInfo) {
+  if (pInfo->pPrevRow == NULL) {
+    return TSDB_CODE_SUCCESS;
+  }
+
+  for (int32_t i = 0; i < taosArrayGetSize(pInfo->pLinearInfo); ++i) {
+    SGroupKeys *pKey = taosArrayGet(pInfo->pPrevRow, i);
+    pKey->isNull = false;
+  }
+
+  pInfo->isPrevRowSet = false;
+
+  return TSDB_CODE_SUCCESS;
+}
+
+static int32_t resetNextRowsKeeper(STimeSliceOperatorInfo* pInfo) {
+  if (pInfo->pNextRow == NULL) {
+    return TSDB_CODE_SUCCESS;
+  }
+
+  for (int32_t i = 0; i < taosArrayGetSize(pInfo->pLinearInfo); ++i) {
+    SGroupKeys *pKey = taosArrayGet(pInfo->pPrevRow, i);
+    pKey->isNull = false;
+  }
+
+  pInfo->isNextRowSet = false;
+
+  return TSDB_CODE_SUCCESS;
+}
+
+static int32_t resetFillLinearInfo(STimeSliceOperatorInfo* pInfo) {
+  if (pInfo->pLinearInfo == NULL) {
+    return TSDB_CODE_SUCCESS;
+  }
+
+  for (int32_t i = 0; i < taosArrayGetSize(pInfo->pLinearInfo); ++i) {
+    SFillLinearInfo *pLinearInfo = taosArrayGet(pInfo->pLinearInfo, i);
+    pLinearInfo->start.key = INT64_MIN;
+    pLinearInfo->end.key = INT64_MIN;
+    pLinearInfo->isStartSet = false;
+    pLinearInfo->isEndSet = false;
+  }
+
+  return TSDB_CODE_SUCCESS;
+}
+
+static int32_t resetKeeperInfo(STimeSliceOperatorInfo* pInfo) {
+  resetPrevRowsKeeper(pInfo);
+  resetNextRowsKeeper(pInfo);
+  resetFillLinearInfo(pInfo);
+
+  return TSDB_CODE_SUCCESS;
+}
+
+static void doTimesliceImpl(SOperatorInfo* pOperator, STimeSliceOperatorInfo* pSliceInfo, SSDataBlock* pBlock,
+                            SExecTaskInfo* pTaskInfo) {
+  SSDataBlock* pResBlock = pSliceInfo->pRes;
+  SInterval*   pInterval = &pSliceInfo->interval;
+
+  SColumnInfoData* pTsCol = taosArrayGet(pBlock->pDataBlock, pSliceInfo->tsCol.slotId);
+  for (int32_t i = 0; i < pBlock->info.rows; ++i) {
+    int64_t ts = *(int64_t*)colDataGetData(pTsCol, i);
+
+    // check for duplicate timestamps
+    if (checkDuplicateTimestamps(pSliceInfo, pTsCol, i, pBlock->info.rows)) {
+      T_LONG_JMP(pTaskInfo->env, TSDB_CODE_FUNC_DUP_TIMESTAMP);
+    }
+
+    if (pSliceInfo->current > pSliceInfo->win.ekey) {
+      break;
+    }
+
+    if (ts == pSliceInfo->current) {
+      addCurrentRowToResult(pSliceInfo, &pOperator->exprSupp, pResBlock, pBlock, i);
+
+      doKeepPrevRows(pSliceInfo, pBlock, i);
+      doKeepLinearInfo(pSliceInfo, pBlock, i);
+
+      pSliceInfo->current =
+          taosTimeAdd(pSliceInfo->current, pInterval->interval, pInterval->intervalUnit, pInterval->precision);
+      if (pSliceInfo->current > pSliceInfo->win.ekey) {
+        break;
+      }
+    } else if (ts < pSliceInfo->current) {
+      // in case of interpolation window starts and ends between two datapoints, fill(prev) need to interpolate
+      doKeepPrevRows(pSliceInfo, pBlock, i);
+      doKeepLinearInfo(pSliceInfo, pBlock, i);
+
+      if (i < pBlock->info.rows - 1) {
+        // in case of interpolation window starts and ends between two datapoints, fill(next) need to interpolate
+        doKeepNextRows(pSliceInfo, pBlock, i + 1);
+        int64_t nextTs = *(int64_t*)colDataGetData(pTsCol, i + 1);
+        if (nextTs > pSliceInfo->current) {
+          while (pSliceInfo->current < nextTs && pSliceInfo->current <= pSliceInfo->win.ekey) {
+            if (!genInterpolationResult(pSliceInfo, &pOperator->exprSupp, pResBlock, pBlock, i, false) &&
+                pSliceInfo->fillType == TSDB_FILL_LINEAR) {
+              break;
+            } else {
+              pSliceInfo->current = taosTimeAdd(pSliceInfo->current, pInterval->interval, pInterval->intervalUnit,
+                                                pInterval->precision);
+            }
+          }
+
+          if (pSliceInfo->current > pSliceInfo->win.ekey) {
+            break;
+          }
+        } else {
+          // ignore current row, and do nothing
+        }
+      } else {  // it is the last row of current block
+        doKeepPrevRows(pSliceInfo, pBlock, i);
+      }
+    } else {  // ts > pSliceInfo->current
+      // in case of interpolation window starts and ends between two datapoints, fill(next) need to interpolate
+      doKeepNextRows(pSliceInfo, pBlock, i);
+      doKeepLinearInfo(pSliceInfo, pBlock, i);
+
+      while (pSliceInfo->current < ts && pSliceInfo->current <= pSliceInfo->win.ekey) {
+        if (!genInterpolationResult(pSliceInfo, &pOperator->exprSupp, pResBlock, pBlock, i, true) &&
+            pSliceInfo->fillType == TSDB_FILL_LINEAR) {
+          break;
+        } else {
+          pSliceInfo->current =
+              taosTimeAdd(pSliceInfo->current, pInterval->interval, pInterval->intervalUnit, pInterval->precision);
+        }
+      }
+
+      // add current row if timestamp match
+      if (ts == pSliceInfo->current && pSliceInfo->current <= pSliceInfo->win.ekey) {
+        addCurrentRowToResult(pSliceInfo, &pOperator->exprSupp, pResBlock, pBlock, i);
+
+        pSliceInfo->current =
+            taosTimeAdd(pSliceInfo->current, pInterval->interval, pInterval->intervalUnit, pInterval->precision);
+      }
+      doKeepPrevRows(pSliceInfo, pBlock, i);
+
+      if (pSliceInfo->current > pSliceInfo->win.ekey) {
+        break;
+      }
+    }
+  }
+}
+
+static void genInterpAfterDataBlock(STimeSliceOperatorInfo* pSliceInfo, SOperatorInfo* pOperator, int32_t index) {
+  SSDataBlock* pResBlock = pSliceInfo->pRes;
+  SInterval*   pInterval = &pSliceInfo->interval;
+
+  while (pSliceInfo->current <= pSliceInfo->win.ekey && pSliceInfo->fillType != TSDB_FILL_NEXT &&
+         pSliceInfo->fillType != TSDB_FILL_LINEAR) {
+    genInterpolationResult(pSliceInfo, &pOperator->exprSupp, pResBlock, NULL, index, false);
+    pSliceInfo->current =
+        taosTimeAdd(pSliceInfo->current, pInterval->interval, pInterval->intervalUnit, pInterval->precision);
+  }
+}
+
+static void copyPrevGroupKey(SExprSupp* pExprSup, SGroupKeys* pGroupKey, SSDataBlock* pSrcBlock) {
+  for (int32_t j = 0; j < pExprSup->numOfExprs; ++j) {
+    SExprInfo* pExprInfo = &pExprSup->pExprInfo[j];
+
+    if (isGroupKeyFunc(pExprInfo)) {
+      int32_t       srcSlot = pExprInfo->base.pParam[0].pCol->slotId;
+      SColumnInfoData* pSrc = taosArrayGet(pSrcBlock->pDataBlock, srcSlot);
+
+      if (colDataIsNull_s(pSrc, 0)) {
+        pGroupKey->isNull = true;
+        break;
+      }
+
+      char* v = colDataGetData(pSrc, 0);
+      if (IS_VAR_DATA_TYPE(pGroupKey->type)) {
+        memcpy(pGroupKey->pData, v, varDataTLen(v));
+      } else {
+        memcpy(pGroupKey->pData, v, pGroupKey->bytes);
+      }
+
+      pGroupKey->isNull = false;
+      break;
+    }
+  }
+}
+
+static void resetTimesliceInfo(STimeSliceOperatorInfo* pSliceInfo) {
+  pSliceInfo->current = pSliceInfo->win.skey;
+  pSliceInfo->prevTsSet = false;
+  resetKeeperInfo(pSliceInfo);
+}
+
 static SSDataBlock* doTimeslice(SOperatorInfo* pOperator) {
   if (pOperator->status == OP_EXEC_DONE) {
     return NULL;
@@ -450,118 +733,62 @@ static SSDataBlock* doTimeslice(SOperatorInfo* pOperator) {
   blockDataCleanup(pResBlock);
 
   while (1) {
-    SSDataBlock* pBlock = downstream->fpSet.getNextFn(downstream);
-    if (pBlock == NULL) {
-      break;
+    if (pSliceInfo->pNextGroupRes != NULL) {
+      setInputDataBlock(pSup, pSliceInfo->pNextGroupRes, order, MAIN_SCAN, true);
+      doTimesliceImpl(pOperator, pSliceInfo, pSliceInfo->pNextGroupRes, pTaskInfo);
+      copyPrevGroupKey(&pOperator->exprSupp, pSliceInfo->pPrevGroupKey, pSliceInfo->pNextGroupRes);
+      pSliceInfo->pNextGroupRes = NULL;
     }
 
-    if (pSliceInfo->scalarSup.pExprInfo != NULL) {
-      SExprSupp* pExprSup = &pSliceInfo->scalarSup;
-      projectApplyFunctions(pExprSup->pExprInfo, pBlock, pBlock, pExprSup->pCtx, pExprSup->numOfExprs, NULL);
-    }
-
-    int32_t code = initKeeperInfo(pSliceInfo, pBlock);
-    if (code != TSDB_CODE_SUCCESS) {
-      T_LONG_JMP(pTaskInfo->env, code);
-    }
-
-    // the pDataBlock are always the same one, no need to call this again
-    setInputDataBlock(pSup, pBlock, order, MAIN_SCAN, true);
-
-    SColumnInfoData* pTsCol = taosArrayGet(pBlock->pDataBlock, pSliceInfo->tsCol.slotId);
-    for (int32_t i = 0; i < pBlock->info.rows; ++i) {
-      int64_t ts = *(int64_t*)colDataGetData(pTsCol, i);
-
-      if (pSliceInfo->current > pSliceInfo->win.ekey) {
+    while (1) {
+      SSDataBlock* pBlock = downstream->fpSet.getNextFn(downstream);
+      if (pBlock == NULL) {
         setOperatorCompleted(pOperator);
         break;
       }
 
-      if (ts == pSliceInfo->current) {
-        addCurrentRowToResult(pSliceInfo, &pOperator->exprSupp, pResBlock, pBlock, i);
-
-        doKeepPrevRows(pSliceInfo, pBlock, i);
-        doKeepLinearInfo(pSliceInfo, pBlock, i);
-
-        pSliceInfo->current =
-            taosTimeAdd(pSliceInfo->current, pInterval->interval, pInterval->intervalUnit, pInterval->precision);
-        if (pSliceInfo->current > pSliceInfo->win.ekey) {
-          setOperatorCompleted(pOperator);
-          break;
-        }
-      } else if (ts < pSliceInfo->current) {
-        // in case of interpolation window starts and ends between two datapoints, fill(prev) need to interpolate
-        doKeepPrevRows(pSliceInfo, pBlock, i);
-        doKeepLinearInfo(pSliceInfo, pBlock, i);
-
-        if (i < pBlock->info.rows - 1) {
-          // in case of interpolation window starts and ends between two datapoints, fill(next) need to interpolate
-          doKeepNextRows(pSliceInfo, pBlock, i + 1);
-          int64_t nextTs = *(int64_t*)colDataGetData(pTsCol, i + 1);
-          if (nextTs > pSliceInfo->current) {
-            while (pSliceInfo->current < nextTs && pSliceInfo->current <= pSliceInfo->win.ekey) {
-              if (!genInterpolationResult(pSliceInfo, &pOperator->exprSupp, pResBlock, false) &&
-                  pSliceInfo->fillType == TSDB_FILL_LINEAR) {
-                break;
-              } else {
-                pSliceInfo->current = taosTimeAdd(pSliceInfo->current, pInterval->interval, pInterval->intervalUnit,
-                                                  pInterval->precision);
-              }
-            }
-
-            if (pSliceInfo->current > pSliceInfo->win.ekey) {
-              setOperatorCompleted(pOperator);
-              break;
-            }
-          } else {
-            // ignore current row, and do nothing
-          }
-        } else {  // it is the last row of current block
-          doKeepPrevRows(pSliceInfo, pBlock, i);
-        }
-      } else {  // ts > pSliceInfo->current
-        // in case of interpolation window starts and ends between two datapoints, fill(next) need to interpolate
-        doKeepNextRows(pSliceInfo, pBlock, i);
-        doKeepLinearInfo(pSliceInfo, pBlock, i);
-
-        while (pSliceInfo->current < ts && pSliceInfo->current <= pSliceInfo->win.ekey) {
-          if (!genInterpolationResult(pSliceInfo, &pOperator->exprSupp, pResBlock, true) &&
-              pSliceInfo->fillType == TSDB_FILL_LINEAR) {
-            break;
-          } else {
-            pSliceInfo->current =
-                taosTimeAdd(pSliceInfo->current, pInterval->interval, pInterval->intervalUnit, pInterval->precision);
-          }
-        }
-
-        // add current row if timestamp match
-        if (ts == pSliceInfo->current && pSliceInfo->current <= pSliceInfo->win.ekey) {
-          addCurrentRowToResult(pSliceInfo, &pOperator->exprSupp, pResBlock, pBlock, i);
-
-          pSliceInfo->current =
-              taosTimeAdd(pSliceInfo->current, pInterval->interval, pInterval->intervalUnit, pInterval->precision);
-        }
-        doKeepPrevRows(pSliceInfo, pBlock, i);
-
-        if (pSliceInfo->current > pSliceInfo->win.ekey) {
-          setOperatorCompleted(pOperator);
+      if (pSliceInfo->groupId == 0 && pBlock->info.id.groupId != 0) {
+        pSliceInfo->groupId = pBlock->info.id.groupId;
+      } else {
+        if (pSliceInfo->groupId != pBlock->info.id.groupId) {
+          pSliceInfo->groupId = pBlock->info.id.groupId;
+          pSliceInfo->pNextGroupRes = pBlock;
           break;
         }
       }
+
+      if (pSliceInfo->scalarSup.pExprInfo != NULL) {
+        SExprSupp* pExprSup = &pSliceInfo->scalarSup;
+        projectApplyFunctions(pExprSup->pExprInfo, pBlock, pBlock, pExprSup->pCtx, pExprSup->numOfExprs, NULL);
+      }
+
+      int32_t code = initKeeperInfo(pSliceInfo, pBlock, &pOperator->exprSupp);
+      if (code != TSDB_CODE_SUCCESS) {
+        T_LONG_JMP(pTaskInfo->env, code);
+      }
+
+      // the pDataBlock are always the same one, no need to call this again
+      setInputDataBlock(pSup, pBlock, order, MAIN_SCAN, true);
+      doTimesliceImpl(pOperator, pSliceInfo, pBlock, pTaskInfo);
+      copyPrevGroupKey(&pOperator->exprSupp, pSliceInfo->pPrevGroupKey, pBlock);
+    }
+
+    // check if need to interpolate after last datablock
+    // except for fill(next), fill(linear)
+    genInterpAfterDataBlock(pSliceInfo, pOperator, 0);
+
+    doFilter(pResBlock, pOperator->exprSupp.pFilterInfo, NULL);
+    if (pOperator->status == OP_EXEC_DONE) {
+      break;
+    }
+
+    // restore initial value for next group
+    resetTimesliceInfo(pSliceInfo);
+    if (pResBlock->info.rows >= 4096) {
+      break;
     }
   }
 
-  // check if need to interpolate after last datablock
-  // except for fill(next), fill(linear)
-  while (pSliceInfo->current <= pSliceInfo->win.ekey && pSliceInfo->fillType != TSDB_FILL_NEXT &&
-         pSliceInfo->fillType != TSDB_FILL_LINEAR) {
-    genInterpolationResult(pSliceInfo, &pOperator->exprSupp, pResBlock, false);
-    pSliceInfo->current =
-        taosTimeAdd(pSliceInfo->current, pInterval->interval, pInterval->intervalUnit, pInterval->precision);
-  }
-
-  doFilter(pResBlock, pOperator->exprSupp.pFilterInfo, NULL);
-
   // restore the value
   setTaskStatus(pOperator->pTaskInfo, TASK_COMPLETED);
   if (pResBlock->info.rows == 0) {
@@ -612,6 +839,11 @@ SOperatorInfo* createTimeSliceOperatorInfo(SOperatorInfo* downstream, SPhysiNode
   pInfo->win = pInterpPhyNode->timeRange;
   pInfo->interval.interval = pInterpPhyNode->interval;
   pInfo->current = pInfo->win.skey;
+  pInfo->prevTsSet = false;
+  pInfo->prevTs = 0;
+  pInfo->groupId = 0;
+  pInfo->pPrevGroupKey = NULL;
+  pInfo->pNextGroupRes = NULL;
 
   if (downstream->operatorType == QUERY_NODE_PHYSICAL_PLAN_TABLE_SCAN) {
     STableScanInfo* pScanInfo = (STableScanInfo*)downstream->info;
@@ -659,6 +891,10 @@ void destroyTimeSliceOperatorInfo(void* param) {
     taosMemoryFree(pKey->end.val);
   }
   taosArrayDestroy(pInfo->pLinearInfo);
+
+  taosMemoryFree(pInfo->pPrevGroupKey->pData);
+  taosMemoryFree(pInfo->pPrevGroupKey);
+
   cleanupExprSupp(&pInfo->scalarSup);
 
   for (int32_t i = 0; i < pInfo->pFillColInfo->numOfFillExpr; ++i) {
diff --git a/source/libs/parser/src/parTranslater.c b/source/libs/parser/src/parTranslater.c
index 6382310e5c..48fc8c6a9c 100644
--- a/source/libs/parser/src/parTranslater.c
+++ b/source/libs/parser/src/parTranslater.c
@@ -1518,9 +1518,7 @@ static int32_t translateInterpFunc(STranslateContext* pCxt, SFunctionNode* pFunc
   SSelectStmt* pSelect = (SSelectStmt*)pCxt->pCurrStmt;
   SNode*       pTable = pSelect->pFromTable;
 
-  if ((NULL != pTable && (QUERY_NODE_REAL_TABLE != nodeType(pTable) ||
-                          (TSDB_CHILD_TABLE != ((SRealTableNode*)pTable)->pMeta->tableType &&
-                           TSDB_NORMAL_TABLE != ((SRealTableNode*)pTable)->pMeta->tableType)))) {
+  if ((NULL != pTable && QUERY_NODE_REAL_TABLE != nodeType(pTable))) {
     return generateSyntaxErrMsgExt(&pCxt->msgBuf, TSDB_CODE_PAR_ONLY_SUPPORT_SINGLE_TABLE,
                                    "%s is only supported in single table query", pFunc->functionName);
   }
diff --git a/tests/system-test/2-query/interp.py b/tests/system-test/2-query/interp.py
index ddf3f2534d..cdbfa0de84 100644
--- a/tests/system-test/2-query/interp.py
+++ b/tests/system-test/2-query/interp.py
@@ -23,6 +23,8 @@ class TDTestCase:
         stbname = "stb"
         ctbname1 = "ctb1"
         ctbname2 = "ctb2"
+        ctbname3 = "ctb3"
+        num_of_ctables = 3
 
         tdSql.prepare()
 
@@ -816,17 +818,26 @@ class TDTestCase:
         )
 
         tdSql.execute(
-            f'''create table if not exists {dbname}.{ctbname2} using {dbname}.{stbname} tags(1)
+            f'''create table if not exists {dbname}.{ctbname2} using {dbname}.{stbname} tags(2)
             '''
         )
 
-        tdSql.execute(f"insert into {dbname}.{ctbname1} values ('2020-02-01 00:00:05', 5, 5, 5, 5, 5.0, 5.0, true, 'varchar', 'nchar')")
-        tdSql.execute(f"insert into {dbname}.{ctbname1} values ('2020-02-01 00:00:10', 10, 10, 10, 10, 10.0, 10.0, true, 'varchar', 'nchar')")
-        tdSql.execute(f"insert into {dbname}.{ctbname1} values ('2020-02-01 00:00:15', 15, 15, 15, 15, 15.0, 15.0, true, 'varchar', 'nchar')")
+        tdSql.execute(
+            f'''create table if not exists {dbname}.{ctbname3} using {dbname}.{stbname} tags(3)
+            '''
+        )
 
-        tdSql.execute(f"insert into {dbname}.{ctbname2} values ('2020-02-02 00:00:05', 5, 5, 5, 5, 5.0, 5.0, true, 'varchar', 'nchar')")
-        tdSql.execute(f"insert into {dbname}.{ctbname2} values ('2020-02-02 00:00:10', 10, 10, 10, 10, 10.0, 10.0, true, 'varchar', 'nchar')")
-        tdSql.execute(f"insert into {dbname}.{ctbname2} values ('2020-02-02 00:00:15', 15, 15, 15, 15, 15.0, 15.0, true, 'varchar', 'nchar')")
+        tdSql.execute(f"insert into {dbname}.{ctbname1} values ('2020-02-01 00:00:01', 1, 1, 1, 1, 1.0, 1.0, true, 'varchar', 'nchar')")
+        tdSql.execute(f"insert into {dbname}.{ctbname1} values ('2020-02-01 00:00:07', 7, 7, 7, 7, 7.0, 7.0, true, 'varchar', 'nchar')")
+        tdSql.execute(f"insert into {dbname}.{ctbname1} values ('2020-02-01 00:00:13', 13, 13, 13, 13, 13.0, 13.0, true, 'varchar', 'nchar')")
+
+        tdSql.execute(f"insert into {dbname}.{ctbname2} values ('2020-02-01 00:00:03', 3, 3, 3, 3, 3.0, 3.0, true, 'varchar', 'nchar')")
+        tdSql.execute(f"insert into {dbname}.{ctbname2} values ('2020-02-01 00:00:09', 9, 9, 9, 9, 9.0, 9.0, true, 'varchar', 'nchar')")
+        tdSql.execute(f"insert into {dbname}.{ctbname2} values ('2020-02-01 00:00:15', 15, 15, 15, 15, 15.0, 15.0, true, 'varchar', 'nchar')")
+
+        tdSql.execute(f"insert into {dbname}.{ctbname3} values ('2020-02-01 00:00:05', 5, 5, 5, 5, 5.0, 5.0, true, 'varchar', 'nchar')")
+        tdSql.execute(f"insert into {dbname}.{ctbname3} values ('2020-02-01 00:00:11', 11, 11, 11, 11, 11.0, 11.0, true, 'varchar', 'nchar')")
+        tdSql.execute(f"insert into {dbname}.{ctbname3} values ('2020-02-01 00:00:17', 17, 17, 17, 17, 17.0, 17.0, true, 'varchar', 'nchar')")
 
 
         tdSql.execute(f"flush database {dbname}");
@@ -834,7 +845,7 @@ class TDTestCase:
         # test fill null
 
         ## | {. | | .} |
-        tdSql.query(f"select interp(c0) from {dbname}.{tbname} range('2020-02-01 00:00:05', '2020-02-11 00:00:05') every(1d) fill(null)")
+        tdSql.query(f"select interp(c0) from {dbname}.{tbname} range('2020-02-01 00:00:05', '2020-02-11 00:00:06') every(1d) fill(null)")
         tdSql.checkRows(11)
         tdSql.checkData(0, 0, 5)
         tdSql.checkData(1, 0, None)
@@ -881,7 +892,7 @@ class TDTestCase:
         # test fill value
 
         ## | {. | | .} |
-        tdSql.query(f"select interp(c0) from {dbname}.{tbname} range('2020-02-01 00:00:05', '2020-02-11 00:00:05') every(1d) fill(value, 1)")
+        tdSql.query(f"select interp(c0) from {dbname}.{tbname} range('2020-02-01 00:00:05', '2020-02-11 00:00:06') every(1d) fill(value, 1)")
         tdSql.checkRows(11)
         tdSql.checkData(0, 0, 5)
         tdSql.checkData(1, 0, 1)
@@ -895,7 +906,7 @@ class TDTestCase:
         tdSql.checkData(9, 0, 1)
         tdSql.checkData(10, 0, 15)
 
-        ## | . | {} | . |
+        # | . | {} | . |
         tdSql.query(f"select interp(c0) from {dbname}.{tbname} range('2020-02-03 00:00:05', '2020-02-07 00:00:05') every(1d) fill(value, 1)")
         tdSql.checkRows(5)
         tdSql.checkData(0, 0, 1)
@@ -928,7 +939,7 @@ class TDTestCase:
         # test fill prev
 
         ## | {. | | .} |
-        tdSql.query(f"select interp(c0) from {dbname}.{tbname} range('2020-02-01 00:00:05', '2020-02-11 00:00:05') every(1d) fill(prev)")
+        tdSql.query(f"select interp(c0) from {dbname}.{tbname} range('2020-02-01 00:00:05', '2020-02-11 00:00:06') every(1d) fill(prev)")
         tdSql.checkRows(11)
         tdSql.checkData(0, 0, 5)
         tdSql.checkData(1, 0, 5)
@@ -973,7 +984,7 @@ class TDTestCase:
         # test fill next
 
         ## | {. | | .} |
-        tdSql.query(f"select interp(c0) from {dbname}.{tbname} range('2020-02-01 00:00:05', '2020-02-11 00:00:05') every(1d) fill(next)")
+        tdSql.query(f"select interp(c0) from {dbname}.{tbname} range('2020-02-01 00:00:05', '2020-02-11 00:00:06') every(1d) fill(next)")
         tdSql.checkRows(11)
         tdSql.checkData(0, 0, 5)
         tdSql.checkData(1, 0, 15)
@@ -1015,7 +1026,7 @@ class TDTestCase:
         # test fill linear
 
         ## | {. | | .} |
-        tdSql.query(f"select interp(c0) from {dbname}.{tbname} range('2020-02-01 00:00:05', '2020-02-11 00:00:05') every(1d) fill(linear)")
+        tdSql.query(f"select interp(c0) from {dbname}.{tbname} range('2020-02-01 00:00:05', '2020-02-11 00:00:06') every(1d) fill(linear)")
         tdSql.checkRows(11)
         tdSql.checkData(0, 0, 5)
         tdSql.checkData(1, 0, 6)
@@ -2391,19 +2402,516 @@ class TDTestCase:
 
 
 
-        tdLog.printNoPrefix("==========step13:stable cases")
+        tdLog.printNoPrefix("==========step13:test stable cases")
 
-        tdSql.error(f"select interp(c0) from {dbname}.{stbname} range('2020-02-01 00:00:04', '2020-02-01 00:00:16') every(1s) fill(null)")
-        #tdSql.checkRows(13)
+        # select interp from supertable
+        tdSql.query(f"select _irowts, _isfilled, interp(c0) from {dbname}.{stbname} range('2020-02-01 00:00:00', '2020-02-01 00:00:18') every(1s) fill(null)")
+        tdSql.checkRows(19)
 
-        #tdSql.query(f"select interp(c0) from {dbname}.{ctbname1} range('2020-02-01 00:00:04', '2020-02-01 00:00:16') every(1s) fill(null)")
-        #tdSql.checkRows(13)
+        tdSql.checkData(0,  2, None)
+        tdSql.checkData(1,  2, 1)
+        tdSql.checkData(2,  2, None)
+        tdSql.checkData(3,  2, 3)
+        tdSql.checkData(4,  2, None)
+        tdSql.checkData(5,  2, 5)
+        tdSql.checkData(6,  2, None)
+        tdSql.checkData(7,  2, 7)
+        tdSql.checkData(8,  2, None)
+        tdSql.checkData(9,  2, 9)
+        tdSql.checkData(10, 2, None)
+        tdSql.checkData(11, 2, 11)
+        tdSql.checkData(12, 2, None)
+        tdSql.checkData(13, 2, 13)
+        tdSql.checkData(14, 2, None)
+        tdSql.checkData(15, 2, 15)
+        tdSql.checkData(16, 2, None)
+        tdSql.checkData(17, 2, 17)
+        tdSql.checkData(18, 2, None)
 
-        tdSql.error(f"select interp(c0) from {dbname}.{stbname} partition by tbname range('2020-02-01 00:00:04', '2020-02-02 00:00:16') every(1s) fill(null)")
-        #tdSql.checkRows(13)
+        tdSql.query(f"select _irowts, _isfilled, interp(c0) from {dbname}.{stbname} range('2020-02-01 00:00:00', '2020-02-01 00:00:18') every(1s) fill(value, 0)")
+        tdSql.checkRows(19)
+
+        tdSql.checkData(0,  2, 0)
+        tdSql.checkData(1,  2, 1)
+        tdSql.checkData(2,  2, 0)
+        tdSql.checkData(3,  2, 3)
+        tdSql.checkData(4,  2, 0)
+        tdSql.checkData(5,  2, 5)
+        tdSql.checkData(6,  2, 0)
+        tdSql.checkData(7,  2, 7)
+        tdSql.checkData(8,  2, 0)
+        tdSql.checkData(9,  2, 9)
+        tdSql.checkData(10, 2, 0)
+        tdSql.checkData(11, 2, 11)
+        tdSql.checkData(12, 2, 0)
+        tdSql.checkData(13, 2, 13)
+        tdSql.checkData(14, 2, 0)
+        tdSql.checkData(15, 2, 15)
+        tdSql.checkData(16, 2, 0)
+        tdSql.checkData(17, 2, 17)
+        tdSql.checkData(18, 2, 0)
+
+        tdSql.query(f"select _irowts, _isfilled, interp(c0) from {dbname}.{stbname} range('2020-02-01 00:00:00', '2020-02-01 00:00:18') every(1s) fill(prev)")
+        tdSql.checkRows(18)
+
+        tdSql.checkData(0,  0, '2020-02-01 00:00:01.000')
+        tdSql.checkData(0,  1, False)
+
+        tdSql.checkData(0,  2, 1)
+        tdSql.checkData(1,  2, 1)
+        tdSql.checkData(2,  2, 3)
+        tdSql.checkData(3,  2, 3)
+        tdSql.checkData(4,  2, 5)
+        tdSql.checkData(5,  2, 5)
+        tdSql.checkData(6,  2, 7)
+        tdSql.checkData(7,  2, 7)
+        tdSql.checkData(8,  2, 9)
+        tdSql.checkData(9,  2, 9)
+        tdSql.checkData(10, 2, 11)
+        tdSql.checkData(11, 2, 11)
+        tdSql.checkData(12, 2, 13)
+        tdSql.checkData(13, 2, 13)
+        tdSql.checkData(14, 2, 15)
+        tdSql.checkData(15, 2, 15)
+        tdSql.checkData(16, 2, 17)
+        tdSql.checkData(17, 2, 17)
+
+        tdSql.checkData(17, 0, '2020-02-01 00:00:18.000')
+        tdSql.checkData(17, 1, True)
+
+        tdSql.query(f"select _irowts, _isfilled, interp(c0) from {dbname}.{stbname} range('2020-02-01 00:00:00', '2020-02-01 00:00:18') every(1s) fill(next)")
+        tdSql.checkRows(18)
+
+        tdSql.checkData(0,  0, '2020-02-01 00:00:00.000')
+        tdSql.checkData(0,  1, True)
+
+        tdSql.checkData(0,  2, 1)
+        tdSql.checkData(1,  2, 1)
+        tdSql.checkData(2,  2, 3)
+        tdSql.checkData(3,  2, 3)
+        tdSql.checkData(4,  2, 5)
+        tdSql.checkData(5,  2, 5)
+        tdSql.checkData(6,  2, 7)
+        tdSql.checkData(7,  2, 7)
+        tdSql.checkData(8,  2, 9)
+        tdSql.checkData(9,  2, 9)
+        tdSql.checkData(10, 2, 11)
+        tdSql.checkData(11, 2, 11)
+        tdSql.checkData(12, 2, 13)
+        tdSql.checkData(13, 2, 13)
+        tdSql.checkData(14, 2, 15)
+        tdSql.checkData(15, 2, 15)
+        tdSql.checkData(16, 2, 17)
+        tdSql.checkData(17, 2, 17)
+
+        tdSql.checkData(17, 0, '2020-02-01 00:00:17.000')
+        tdSql.checkData(17, 1, False)
+
+        tdSql.query(f"select _irowts, _isfilled, interp(c0) from {dbname}.{stbname} range('2020-02-01 00:00:00', '2020-02-01 00:00:18') every(1s) fill(linear)")
+        tdSql.checkRows(17)
+
+        tdSql.checkData(0,  2, 1)
+        tdSql.checkData(1,  2, 2)
+        tdSql.checkData(2,  2, 3)
+        tdSql.checkData(3,  2, 4)
+        tdSql.checkData(4,  2, 5)
+        tdSql.checkData(5,  2, 6)
+        tdSql.checkData(6,  2, 7)
+        tdSql.checkData(7,  2, 8)
+        tdSql.checkData(8,  2, 9)
+        tdSql.checkData(9,  2, 10)
+        tdSql.checkData(10, 2, 11)
+        tdSql.checkData(11, 2, 12)
+        tdSql.checkData(12, 2, 13)
+        tdSql.checkData(13, 2, 14)
+        tdSql.checkData(14, 2, 15)
+        tdSql.checkData(15, 2, 16)
+        tdSql.checkData(16, 2, 17)
+
+        # select interp from supertable partition by tbname
+
+        tdSql.query(f"select tbname, _irowts, _isfilled, interp(c0) from {dbname}.{stbname} partition by tbname range('2020-02-01 00:00:00', '2020-02-01 00:00:18') every(1s) fill(null)")
+
+        point_idx = {1, 7, 13, 22, 28, 34, 43, 49, 55}
+        point_dict = {1:1, 7:7, 13:13, 22:3, 28:9, 34:15, 43:5, 49:11, 55:17}
+        rows_per_partition = 19
+        tdSql.checkRows(rows_per_partition * num_of_ctables)
+        for i in range(num_of_ctables):
+          for j in range(rows_per_partition):
+            row = j + i * rows_per_partition
+            tdSql.checkData(row,  0, f'ctb{i + 1}')
+            tdSql.checkData(j,  1, f'2020-02-01 00:00:{j}.000')
+            if row in point_idx:
+                tdSql.checkData(row, 2, False)
+            else:
+                tdSql.checkData(row, 2, True)
+
+            if row in point_idx:
+                tdSql.checkData(row, 3, point_dict[row])
+            else:
+                tdSql.checkData(row, 3, None)
+
+        tdSql.query(f"select tbname, _irowts, _isfilled, interp(c0) from {dbname}.{stbname} partition by tbname range('2020-02-01 00:00:00', '2020-02-01 00:00:18') every(1s) fill(value, 0)")
+
+        point_idx = {1, 7, 13, 22, 28, 34, 43, 49, 55}
+        point_dict = {1:1, 7:7, 13:13, 22:3, 28:9, 34:15, 43:5, 49:11, 55:17}
+        rows_per_partition = 19
+        tdSql.checkRows(rows_per_partition * num_of_ctables)
+        for i in range(num_of_ctables):
+          for j in range(rows_per_partition):
+            row = j + i * rows_per_partition
+            tdSql.checkData(row,  0, f'ctb{i + 1}')
+            tdSql.checkData(j,  1, f'2020-02-01 00:00:{j}.000')
+            if row in point_idx:
+                tdSql.checkData(row, 2, False)
+            else:
+                tdSql.checkData(row, 2, True)
+
+            if row in point_idx:
+                tdSql.checkData(row, 3, point_dict[row])
+            else:
+                tdSql.checkData(row, 3, 0)
+
+        tdSql.query(f"select tbname, _irowts, _isfilled, interp(c0) from {dbname}.{stbname} partition by tbname range('2020-02-01 00:00:00', '2020-02-01 00:00:18') every(1s) fill(prev)")
+
+        tdSql.checkRows(48)
+        for i in range(0, 18):
+            tdSql.checkData(i, 0, 'ctb1')
+
+        for i in range(18, 34):
+            tdSql.checkData(i, 0, 'ctb2')
+
+        for i in range(34, 48):
+            tdSql.checkData(i, 0, 'ctb3')
+
+        tdSql.checkData(0,  1, '2020-02-01 00:00:01.000')
+        tdSql.checkData(17, 1, '2020-02-01 00:00:18.000')
+
+        tdSql.checkData(18, 1, '2020-02-01 00:00:03.000')
+        tdSql.checkData(33, 1, '2020-02-01 00:00:18.000')
+
+        tdSql.checkData(34, 1, '2020-02-01 00:00:05.000')
+        tdSql.checkData(47, 1, '2020-02-01 00:00:18.000')
+
+        for i in range(0, 6):
+            tdSql.checkData(i, 3, 1)
+
+        for i in range(6, 12):
+            tdSql.checkData(i, 3, 7)
+
+        for i in range(12, 18):
+            tdSql.checkData(i, 3, 13)
+
+        for i in range(18, 24):
+            tdSql.checkData(i, 3, 3)
+
+        for i in range(24, 30):
+            tdSql.checkData(i, 3, 9)
+
+        for i in range(30, 34):
+            tdSql.checkData(i, 3, 15)
+
+        for i in range(34, 40):
+            tdSql.checkData(i, 3, 5)
+
+        for i in range(40, 46):
+            tdSql.checkData(i, 3, 11)
+
+        for i in range(46, 48):
+            tdSql.checkData(i, 3, 17)
+
+        tdSql.query(f"select tbname, _irowts, _isfilled, interp(c0) from {dbname}.{stbname} partition by tbname range('2020-02-01 00:00:00', '2020-02-01 00:00:18') every(1s) fill(next)")
+
+        tdSql.checkRows(48)
+        for i in range(0, 14):
+            tdSql.checkData(i, 0, 'ctb1')
+
+        for i in range(14, 30):
+            tdSql.checkData(i, 0, 'ctb2')
+
+        for i in range(30, 48):
+            tdSql.checkData(i, 0, 'ctb3')
+
+        tdSql.checkData(0,  1, '2020-02-01 00:00:00.000')
+        tdSql.checkData(13, 1, '2020-02-01 00:00:13.000')
+
+        tdSql.checkData(14, 1, '2020-02-01 00:00:00.000')
+        tdSql.checkData(29, 1, '2020-02-01 00:00:15.000')
+
+        tdSql.checkData(30, 1, '2020-02-01 00:00:00.000')
+        tdSql.checkData(47, 1, '2020-02-01 00:00:17.000')
+
+        for i in range(0, 2):
+            tdSql.checkData(i, 3, 1)
+
+        for i in range(2, 8):
+            tdSql.checkData(i, 3, 7)
+
+        for i in range(8, 14):
+            tdSql.checkData(i, 3, 13)
+
+        for i in range(14, 18):
+            tdSql.checkData(i, 3, 3)
+
+        for i in range(18, 24):
+            tdSql.checkData(i, 3, 9)
+
+        for i in range(24, 30):
+            tdSql.checkData(i, 3, 15)
+
+        for i in range(30, 36):
+            tdSql.checkData(i, 3, 5)
+
+        for i in range(36, 42):
+            tdSql.checkData(i, 3, 11)
+
+        for i in range(42, 48):
+            tdSql.checkData(i, 3, 17)
+
+        tdSql.query(f"select tbname, _irowts, _isfilled, interp(c0) from {dbname}.{stbname} partition by tbname range('2020-02-01 00:00:00', '2020-02-01 00:00:18') every(1s) fill(linear)")
+
+        tdSql.checkRows(39)
+        for i in range(0, 13):
+            tdSql.checkData(i, 0, 'ctb1')
+
+        for i in range(13, 26):
+            tdSql.checkData(i, 0, 'ctb2')
+
+        for i in range(26, 39):
+            tdSql.checkData(i, 0, 'ctb3')
+
+        tdSql.checkData(0,  1, '2020-02-01 00:00:01.000')
+        tdSql.checkData(12, 1, '2020-02-01 00:00:13.000')
+
+        tdSql.checkData(13, 1, '2020-02-01 00:00:03.000')
+        tdSql.checkData(25, 1, '2020-02-01 00:00:15.000')
+
+        tdSql.checkData(26, 1, '2020-02-01 00:00:05.000')
+        tdSql.checkData(38, 1, '2020-02-01 00:00:17.000')
+
+        for i in range(0, 13):
+            tdSql.checkData(i, 3, i + 1)
+
+        for i in range(13, 26):
+            tdSql.checkData(i, 3, i - 10)
+
+        for i in range(26, 39):
+            tdSql.checkData(i, 3, i - 21)
+
+        # select interp from supertable partition by column
+
+        tdSql.query(f"select c0, _irowts, _isfilled, interp(c0) from {dbname}.{stbname} partition by c0 range('2020-02-01 00:00:00', '2020-02-01 00:00:18') every(1s) fill(null)")
+        tdSql.checkRows(171)
+
+        tdSql.query(f"select c0, _irowts, _isfilled, interp(c0) from {dbname}.{stbname} partition by c0 range('2020-02-01 00:00:00', '2020-02-01 00:00:18') every(1s) fill(value, 0)")
+        tdSql.checkRows(171)
+
+        tdSql.query(f"select c0, _irowts, _isfilled, interp(c0) from {dbname}.{stbname} partition by c0 range('2020-02-01 00:00:00', '2020-02-01 00:00:18') every(1s) fill(prev)")
+        tdSql.checkRows(90)
+
+        tdSql.query(f"select c0, _irowts, _isfilled, interp(c0) from {dbname}.{stbname} partition by c0 range('2020-02-01 00:00:00', '2020-02-01 00:00:18') every(1s) fill(next)")
+        tdSql.checkRows(90)
+
+        tdSql.query(f"select c0, _irowts, _isfilled, interp(c0) from {dbname}.{stbname} partition by c0 range('2020-02-01 00:00:00', '2020-02-01 00:00:18') every(1s) fill(linear)")
+        tdSql.checkRows(9)
+
+        # select interp from supertable partition by tag
+
+        tdSql.query(f"select t1, _irowts, _isfilled, interp(c0) from {dbname}.{stbname} partition by t1 range('2020-02-01 00:00:00', '2020-02-01 00:00:18') every(1s) fill(null)")
+        tdSql.checkRows(57)
+
+        tdSql.query(f"select t1, _irowts, _isfilled, interp(c0) from {dbname}.{stbname} partition by t1 range('2020-02-01 00:00:00', '2020-02-01 00:00:18') every(1s) fill(value, 0)")
+        tdSql.checkRows(57)
+
+        tdSql.query(f"select t1, _irowts, _isfilled, interp(c0) from {dbname}.{stbname} partition by t1 range('2020-02-01 00:00:00', '2020-02-01 00:00:18') every(1s) fill(prev)")
+        tdSql.checkRows(48)
+
+        tdSql.query(f"select t1, _irowts, _isfilled, interp(c0) from {dbname}.{stbname} partition by t1 range('2020-02-01 00:00:00', '2020-02-01 00:00:18') every(1s) fill(next)")
+        tdSql.checkRows(48)
+
+        tdSql.query(f"select t1, _irowts, _isfilled, interp(c0) from {dbname}.{stbname} partition by t1 range('2020-02-01 00:00:00', '2020-02-01 00:00:18') every(1s) fill(linear)")
+        tdSql.checkRows(39)
+
+        # select interp from supertable filter
+
+        tdSql.query(f"select _irowts, _isfilled, interp(c0) from {dbname}.{stbname} where ts between '2020-02-01 00:00:01.000' and '2020-02-01 00:00:13.000' range('2020-02-01 00:00:00', '2020-02-01 00:00:18') every(1s) fill(linear)")
+        tdSql.checkRows(13)
+
+        for i in range(13):
+          tdSql.checkData(i, 0, f'2020-02-01 00:00:{i + 1}.000')
+          tdSql.checkData(i, 2, i + 1)
+
+        tdSql.query(f"select _irowts, _isfilled, interp(c0) from {dbname}.{stbname} where c0 <= 13 range('2020-02-01 00:00:00', '2020-02-01 00:00:18') every(1s) fill(linear)")
+        tdSql.checkRows(13)
+
+        for i in range(13):
+          tdSql.checkData(i, 0, f'2020-02-01 00:00:{i + 1}.000')
+          tdSql.checkData(i, 2, i + 1)
+
+        tdSql.query(f"select _irowts, _isfilled, interp(c0) from {dbname}.{stbname} where t1 = 1 range('2020-02-01 00:00:00', '2020-02-01 00:00:18') every(1s) fill(linear)")
+        tdSql.checkRows(13)
+
+        for i in range(13):
+          tdSql.checkData(i, 0, f'2020-02-01 00:00:{i + 1}.000')
+          tdSql.checkData(i, 2, i + 1)
+
+        tdSql.query(f"select _irowts, _isfilled, interp(c0) from {dbname}.{stbname} where tbname = 'ctb1' range('2020-02-01 00:00:00', '2020-02-01 00:00:18') every(1s) fill(linear)")
+        tdSql.checkRows(13)
+
+        for i in range(13):
+          tdSql.checkData(i, 0, f'2020-02-01 00:00:{i + 1}.000')
+          tdSql.checkData(i, 2, i + 1)
+
+        tdSql.query(f"select _irowts, _isfilled, interp(c0) from {dbname}.{stbname} where ts between '2020-02-01 00:00:01.000' and '2020-02-01 00:00:13.000' partition by tbname range('2020-02-01 00:00:00', '2020-02-01 00:00:18') every(1s) fill(linear)")
+        tdSql.checkRows(27)
+
+        for i in range(13):
+          tdSql.checkData(i, 0, f'2020-02-01 00:00:{i + 1}.000')
+          tdSql.checkData(i, 2, i + 1)
+
+        tdSql.query(f"select _irowts, _isfilled, interp(c0) from {dbname}.{stbname} where c0 <= 13 partition by tbname range('2020-02-01 00:00:00', '2020-02-01 00:00:18') every(1s) fill(linear)")
+        tdSql.checkRows(27)
+
+        for i in range(13):
+          tdSql.checkData(i, 0, f'2020-02-01 00:00:{i + 1}.000')
+          tdSql.checkData(i, 2, i + 1)
+
+        tdSql.query(f"select _irowts, _isfilled, interp(c0) from {dbname}.{stbname} where t1 = 1 partition by tbname range('2020-02-01 00:00:00', '2020-02-01 00:00:18') every(1s) fill(linear)")
+        tdSql.checkRows(13)
+
+        for i in range(13):
+          tdSql.checkData(i, 0, f'2020-02-01 00:00:{i + 1}.000')
+          tdSql.checkData(i, 2, i + 1)
+
+        tdSql.query(f"select _irowts, _isfilled, interp(c0) from {dbname}.{stbname} where tbname = 'ctb1' partition by tbname range('2020-02-01 00:00:00', '2020-02-01 00:00:18') every(1s) fill(linear)")
+        tdSql.checkRows(13)
+
+        for i in range(13):
+          tdSql.checkData(i, 0, f'2020-02-01 00:00:{i + 1}.000')
+          tdSql.checkData(i, 2, i + 1)
+
+        # select interp from supertable filter limit
+
+        tdSql.query(f"select _irowts, _isfilled, interp(c0) from {dbname}.{stbname} range('2020-02-01 00:00:00', '2020-02-01 00:00:18') every(1s) fill(linear) limit 13")
+        tdSql.checkRows(13)
+
+        for i in range(13):
+          tdSql.checkData(i, 0, f'2020-02-01 00:00:{i + 1}.000')
+          tdSql.checkData(i, 2, i + 1)
+
+        tdSql.query(f"select _irowts, _isfilled, interp(c0) from {dbname}.{stbname} range('2020-02-01 00:00:00', '2020-02-01 00:00:18') every(1s) fill(linear) limit 20")
+        tdSql.checkRows(17)
+
+        for i in range(17):
+          tdSql.checkData(i, 0, f'2020-02-01 00:00:{i + 1}.000')
+          tdSql.checkData(i, 2, i + 1)
+
+        tdSql.query(f"select _irowts, _isfilled, interp(c0) from {dbname}.{stbname} where ts between '2020-02-01 00:00:01.000' and '2020-02-01 00:00:13.000' range('2020-02-01 00:00:00', '2020-02-01 00:00:18') every(1s) fill(linear) limit 10")
+        tdSql.checkRows(10)
+
+        for i in range(10):
+          tdSql.checkData(i, 0, f'2020-02-01 00:00:{i + 1}.000')
+          tdSql.checkData(i, 2, i + 1)
+
+        tdSql.query(f"select _irowts, _isfilled, interp(c0) from {dbname}.{stbname} where c0 <= 13 range('2020-02-01 00:00:00', '2020-02-01 00:00:18') every(1s) fill(linear) limit 10")
+        tdSql.checkRows(10)
+
+        for i in range(10):
+          tdSql.checkData(i, 0, f'2020-02-01 00:00:{i + 1}.000')
+          tdSql.checkData(i, 2, i + 1)
+
+        tdSql.query(f"select _irowts, _isfilled, interp(c0) from {dbname}.{stbname} where t1 = 1 range('2020-02-01 00:00:00', '2020-02-01 00:00:18') every(1s) fill(linear) limit 10")
+        tdSql.checkRows(10)
+
+        for i in range(10):
+          tdSql.checkData(i, 0, f'2020-02-01 00:00:{i + 1}.000')
+          tdSql.checkData(i, 2, i + 1)
+
+        tdSql.query(f"select _irowts, _isfilled, interp(c0) from {dbname}.{stbname} where tbname = 'ctb1' range('2020-02-01 00:00:00', '2020-02-01 00:00:18') every(1s) fill(linear) limit 10")
+        tdSql.checkRows(10)
+
+        for i in range(10):
+          tdSql.checkData(i, 0, f'2020-02-01 00:00:{i + 1}.000')
+          tdSql.checkData(i, 2, i + 1)
+
+        tdSql.query(f"select _irowts, _isfilled, interp(c0) from {dbname}.{stbname} partition by tbname range('2020-02-01 00:00:00', '2020-02-01 00:00:18') every(1s) fill(linear) limit 13")
+        tdSql.checkRows(13)
+
+        for i in range(13):
+          tdSql.checkData(i, 0, f'2020-02-01 00:00:{i + 1}.000')
+          tdSql.checkData(i, 2, i + 1)
+
+        tdSql.query(f"select _irowts, _isfilled, interp(c0) from {dbname}.{stbname} partition by tbname range('2020-02-01 00:00:00', '2020-02-01 00:00:18') every(1s) fill(linear) limit 40")
+        tdSql.checkRows(39)
+
+        tdSql.query(f"select _irowts, _isfilled, interp(c0) from {dbname}.{stbname} where ts between '2020-02-01 00:00:01.000' and '2020-02-01 00:00:13.000' partition by tbname range('2020-02-01 00:00:00', '2020-02-01 00:00:18') every(1s) fill(linear) limit 10")
+        tdSql.checkRows(10)
+
+        for i in range(10):
+          tdSql.checkData(i, 0, f'2020-02-01 00:00:{i + 1}.000')
+          tdSql.checkData(i, 2, i + 1)
+
+        tdSql.query(f"select _irowts, _isfilled, interp(c0) from {dbname}.{stbname} where c0 <= 13 partition by tbname range('2020-02-01 00:00:00', '2020-02-01 00:00:18') every(1s) fill(linear) limit 10")
+        tdSql.checkRows(10)
+
+        for i in range(10):
+          tdSql.checkData(i, 0, f'2020-02-01 00:00:{i + 1}.000')
+          tdSql.checkData(i, 2, i + 1)
+
+        tdSql.query(f"select _irowts, _isfilled, interp(c0) from {dbname}.{stbname} where t1 = 1 partition by tbname range('2020-02-01 00:00:00', '2020-02-01 00:00:18') every(1s) fill(linear) limit 10")
+        tdSql.checkRows(10)
+
+        for i in range(10):
+          tdSql.checkData(i, 0, f'2020-02-01 00:00:{i + 1}.000')
+          tdSql.checkData(i, 2, i + 1)
+
+        tdSql.query(f"select _irowts, _isfilled, interp(c0) from {dbname}.{stbname} where tbname = 'ctb1' partition by tbname range('2020-02-01 00:00:00', '2020-02-01 00:00:18') every(1s) fill(linear) limit 10")
+        tdSql.checkRows(10)
+
+        for i in range(10):
+          tdSql.checkData(i, 0, f'2020-02-01 00:00:{i + 1}.000')
+          tdSql.checkData(i, 2, i + 1)
+
+        # select interp from supertable with scalar expression
+
+        tdSql.query(f"select _irowts, _isfilled, interp(1 + 1) from {dbname}.{stbname} range('2020-02-01 00:00:00', '2020-02-01 00:00:18') every(1s) fill(linear)")
+        tdSql.checkRows(17)
+
+        for i in range(17):
+          tdSql.checkData(i, 0, f'2020-02-01 00:00:{i + 1}.000')
+          tdSql.checkData(i, 2, 2.0)
+
+        tdSql.query(f"select _irowts, _isfilled, interp(c0 + 1) from {dbname}.{stbname} range('2020-02-01 00:00:00', '2020-02-01 00:00:18') every(1s) fill(linear)")
+        tdSql.checkRows(17)
+
+        for i in range(17):
+          tdSql.checkData(i, 0, f'2020-02-01 00:00:{i + 1}.000')
+          tdSql.checkData(i, 2, i + 2)
+
+        tdSql.query(f"select _irowts, _isfilled, interp(c0 * 2) from {dbname}.{stbname} range('2020-02-01 00:00:00', '2020-02-01 00:00:18') every(1s) fill(linear)")
+        tdSql.checkRows(17)
+
+        for i in range(17):
+          tdSql.checkData(i, 0, f'2020-02-01 00:00:{i + 1}.000')
+          tdSql.checkData(i, 2, (i + 1) * 2)
+
+        tdSql.query(f"select _irowts, _isfilled, interp(c0 + c1) from {dbname}.{stbname} range('2020-02-01 00:00:00', '2020-02-01 00:00:18') every(1s) fill(linear)")
+        tdSql.checkRows(17)
+
+        for i in range(17):
+          tdSql.checkData(i, 0, f'2020-02-01 00:00:{i + 1}.000')
+          tdSql.checkData(i, 2, (i + 1) * 2)
+
+        # check duplicate timestamp
+
+        # add duplicate timestamp for different child tables
+        tdSql.execute(f"insert into {dbname}.{ctbname1} values ('2020-02-01 00:00:15', 15, 15, 15, 15, 15.0, 15.0, true, 'varchar', 'nchar')")
+
+        tdSql.query(f"select _irowts, _isfilled, interp(c0) from {dbname}.{stbname} range('2020-02-01 00:00:00', '2020-02-01 00:00:14') every(1s) fill(null)")
+        tdSql.error(f"select _irowts, _isfilled, interp(c0) from {dbname}.{stbname} range('2020-02-01 00:00:00', '2020-02-01 00:00:15') every(1s) fill(null)")
+        tdSql.error(f"select _irowts, _isfilled, interp(c0) from {dbname}.{stbname} range('2020-02-01 00:00:00', '2020-02-01 00:00:18') every(1s) fill(null)")
+        tdSql.query(f"select _irowts, _isfilled, interp(c0) from {dbname}.{stbname} partition by tbname range('2020-02-01 00:00:00', '2020-02-01 00:00:18') every(1s) fill(null)")
 
-        #tdSql.query(f"select _irowts,interp(c0) from {dbname}.{stbname} partition by tbname range('2020-02-01 00:00:04', '2020-02-02 00:00:16') every(1h) fill(prev)")
-        #tdSql.query(f"select tbname,_irowts,interp(c0) from {dbname}.{stbname} partition by tbname range('2020-02-01 00:00:04', '2020-02-02 00:00:16') every(1h) fill(prev)")
 
         tdLog.printNoPrefix("======step 14: test interp pseudo columns")
         tdSql.error(f"select _irowts, c6 from {dbname}.{tbname}")