diff --git a/source/libs/command/inc/commandInt.h b/source/libs/command/inc/commandInt.h
index 6acf19218d..764553f1e9 100644
--- a/source/libs/command/inc/commandInt.h
+++ b/source/libs/command/inc/commandInt.h
@@ -64,6 +64,9 @@ extern "C" {
 #define EXPLAIN_IGNORE_GROUPID_FORMAT "Ignore Group Id: %s"
 #define EXPLAIN_PARTITION_KETS_FORMAT "Partition Key: "
 #define EXPLAIN_INTERP_FORMAT "Interp"
+#define EXPLAIN_EVENT_FORMAT "Event"
+#define EXPLAIN_EVENT_START_FORMAT "Start Cond: "
+#define EXPLAIN_EVENT_END_FORMAT "End Cond: "
 
 #define EXPLAIN_PLANNING_TIME_FORMAT "Planning Time: %.3f ms"
 #define EXPLAIN_EXEC_TIME_FORMAT "Execution Time: %.3f ms"
diff --git a/source/libs/command/src/explain.c b/source/libs/command/src/explain.c
index 38222112a1..fdbbcad968 100644
--- a/source/libs/command/src/explain.c
+++ b/source/libs/command/src/explain.c
@@ -114,129 +114,7 @@ _return:
 
 int32_t qExplainGenerateResChildren(SPhysiNode *pNode, SExplainGroup *group, SNodeList **pChildren) {
   int32_t    tlen = 0;
-  SNodeList *pPhysiChildren = NULL;
-
-  switch (pNode->type) {
-    case QUERY_NODE_PHYSICAL_PLAN_TAG_SCAN: {
-      STagScanPhysiNode *pTagScanNode = (STagScanPhysiNode *)pNode;
-      pPhysiChildren = pTagScanNode->node.pChildren;
-      break;
-    }
-    case QUERY_NODE_PHYSICAL_PLAN_TABLE_SEQ_SCAN:
-    case QUERY_NODE_PHYSICAL_PLAN_TABLE_SCAN: {
-      STableScanPhysiNode *pTblScanNode = (STableScanPhysiNode *)pNode;
-      pPhysiChildren = pTblScanNode->scan.node.pChildren;
-      break;
-    }
-    case QUERY_NODE_PHYSICAL_PLAN_SYSTABLE_SCAN: {
-      SSystemTableScanPhysiNode *pSTblScanNode = (SSystemTableScanPhysiNode *)pNode;
-      pPhysiChildren = pSTblScanNode->scan.node.pChildren;
-      break;
-    }
-    case QUERY_NODE_PHYSICAL_PLAN_PROJECT: {
-      SProjectPhysiNode *pPrjNode = (SProjectPhysiNode *)pNode;
-      pPhysiChildren = pPrjNode->node.pChildren;
-      break;
-    }
-    case QUERY_NODE_PHYSICAL_PLAN_MERGE_JOIN: {
-      SSortMergeJoinPhysiNode *pJoinNode = (SSortMergeJoinPhysiNode *)pNode;
-      pPhysiChildren = pJoinNode->node.pChildren;
-      break;
-    }
-    case QUERY_NODE_PHYSICAL_PLAN_HASH_AGG: {
-      SAggPhysiNode *pAggNode = (SAggPhysiNode *)pNode;
-      pPhysiChildren = pAggNode->node.pChildren;
-      break;
-    }
-    case QUERY_NODE_PHYSICAL_PLAN_EXCHANGE: {
-      SExchangePhysiNode *pExchNode = (SExchangePhysiNode *)pNode;
-      pPhysiChildren = pExchNode->node.pChildren;
-      break;
-    }
-    case QUERY_NODE_PHYSICAL_PLAN_SORT: {
-      SSortPhysiNode *pSortNode = (SSortPhysiNode *)pNode;
-      pPhysiChildren = pSortNode->node.pChildren;
-      break;
-    }
-    case QUERY_NODE_PHYSICAL_PLAN_HASH_INTERVAL: {
-      SIntervalPhysiNode *pIntNode = (SIntervalPhysiNode *)pNode;
-      pPhysiChildren = pIntNode->window.node.pChildren;
-      break;
-    }
-    case QUERY_NODE_PHYSICAL_PLAN_MERGE_SESSION: {
-      SSessionWinodwPhysiNode *pSessNode = (SSessionWinodwPhysiNode *)pNode;
-      pPhysiChildren = pSessNode->window.node.pChildren;
-      break;
-    }
-    case QUERY_NODE_PHYSICAL_PLAN_MERGE_STATE: {
-      SStateWinodwPhysiNode *pStateNode = (SStateWinodwPhysiNode *)pNode;
-      pPhysiChildren = pStateNode->window.node.pChildren;
-      break;
-    }
-    case QUERY_NODE_PHYSICAL_PLAN_PARTITION: {
-      SPartitionPhysiNode *partitionPhysiNode = (SPartitionPhysiNode *)pNode;
-      pPhysiChildren = partitionPhysiNode->node.pChildren;
-      break;
-    }
-    case QUERY_NODE_PHYSICAL_PLAN_MERGE: {
-      SMergePhysiNode *mergePhysiNode = (SMergePhysiNode *)pNode;
-      pPhysiChildren = mergePhysiNode->node.pChildren;
-      break;
-    }
-    case QUERY_NODE_PHYSICAL_PLAN_INDEF_ROWS_FUNC: {
-      SIndefRowsFuncPhysiNode *indefPhysiNode = (SIndefRowsFuncPhysiNode *)pNode;
-      pPhysiChildren = indefPhysiNode->node.pChildren;
-      break;
-    }
-    case QUERY_NODE_PHYSICAL_PLAN_MERGE_ALIGNED_INTERVAL: {
-      SMergeAlignedIntervalPhysiNode *intPhysiNode = (SMergeAlignedIntervalPhysiNode *)pNode;
-      pPhysiChildren = intPhysiNode->window.node.pChildren;
-      break;
-    }
-    case QUERY_NODE_PHYSICAL_PLAN_FILL: {
-      SFillPhysiNode *fillPhysiNode = (SFillPhysiNode *)pNode;
-      pPhysiChildren = fillPhysiNode->node.pChildren;
-      break;
-    }
-    case QUERY_NODE_PHYSICAL_PLAN_TABLE_MERGE_SCAN: {
-      STableMergeScanPhysiNode *mergePhysiNode = (STableMergeScanPhysiNode *)pNode;
-      pPhysiChildren = mergePhysiNode->scan.node.pChildren;
-      break;
-    }
-    case QUERY_NODE_PHYSICAL_PLAN_BLOCK_DIST_SCAN: {
-      SBlockDistScanPhysiNode *distPhysiNode = (SBlockDistScanPhysiNode *)pNode;
-      pPhysiChildren = distPhysiNode->node.pChildren;
-      break;
-    }
-    case QUERY_NODE_PHYSICAL_PLAN_LAST_ROW_SCAN: {
-      SLastRowScanPhysiNode *lastRowPhysiNode = (SLastRowScanPhysiNode *)pNode;
-      pPhysiChildren = lastRowPhysiNode->scan.node.pChildren;
-      break;
-    }
-    case QUERY_NODE_PHYSICAL_PLAN_TABLE_COUNT_SCAN: {
-      STableCountScanPhysiNode *tableCountPhysiNode = (STableCountScanPhysiNode *)pNode;
-      pPhysiChildren = tableCountPhysiNode->scan.node.pChildren;
-      break;
-    }
-    case QUERY_NODE_PHYSICAL_PLAN_GROUP_SORT: {
-      SGroupSortPhysiNode *groupSortPhysiNode = (SGroupSortPhysiNode *)pNode;
-      pPhysiChildren = groupSortPhysiNode->node.pChildren;
-      break;
-    }
-    case QUERY_NODE_PHYSICAL_PLAN_MERGE_INTERVAL: {
-      SMergeIntervalPhysiNode *mergeIntPhysiNode = (SMergeIntervalPhysiNode *)pNode;
-      pPhysiChildren = mergeIntPhysiNode->window.node.pChildren;
-      break;
-    }
-    case QUERY_NODE_PHYSICAL_PLAN_INTERP_FUNC: {
-      SInterpFuncPhysiNode *interpPhysiNode = (SInterpFuncPhysiNode *)pNode;
-      pPhysiChildren = interpPhysiNode->node.pChildren;
-      break;
-    }
-    default:
-      qError("not supported physical node type %d", pNode->type);
-      QRY_ERR_RET(TSDB_CODE_APP_ERROR);
-  }
+  SNodeList *pPhysiChildren = pNode->pChildren;
 
   if (pPhysiChildren) {
     *pChildren = nodesMakeList();
@@ -1583,6 +1461,36 @@ int32_t qExplainResNodeToRowsImpl(SExplainResNode *pResNode, SExplainCtx *ctx, i
       }
       break;
     }
+    case QUERY_NODE_PHYSICAL_PLAN_MERGE_EVENT: {
+      SEventWinodwPhysiNode *pEventNode = (SEventWinodwPhysiNode *)pNode;
+      EXPLAIN_ROW_NEW(level, EXPLAIN_EVENT_FORMAT);
+      EXPLAIN_ROW_APPEND(EXPLAIN_LEFT_PARENTHESIS_FORMAT);
+      if (pResNode->pExecInfo) {
+        QRY_ERR_RET(qExplainBufAppendExecInfo(pResNode->pExecInfo, tbuf, &tlen));
+        EXPLAIN_ROW_APPEND(EXPLAIN_BLANK_FORMAT);
+      }
+      EXPLAIN_ROW_APPEND(EXPLAIN_FUNCTIONS_FORMAT, pEventNode->window.pFuncs->length);
+      EXPLAIN_ROW_APPEND(EXPLAIN_BLANK_FORMAT);
+      EXPLAIN_ROW_APPEND(EXPLAIN_WIDTH_FORMAT, pEventNode->window.node.pOutputDataBlockDesc->totalRowSize);
+      EXPLAIN_ROW_APPEND(EXPLAIN_RIGHT_PARENTHESIS_FORMAT);
+      EXPLAIN_ROW_END();
+      QRY_ERR_RET(qExplainResAppendRow(ctx, tbuf, tlen, level));
+
+      if (verbose) {
+        EXPLAIN_ROW_NEW(level + 1, EXPLAIN_EVENT_START_FORMAT);
+        QRY_ERR_RET(nodesNodeToSQL(pEventNode->pStartCond, tbuf + VARSTR_HEADER_SIZE,
+                                    TSDB_EXPLAIN_RESULT_ROW_SIZE, &tlen));
+        EXPLAIN_ROW_END();
+        QRY_ERR_RET(qExplainResAppendRow(ctx, tbuf, tlen, level + 1));
+        
+        EXPLAIN_ROW_NEW(level + 1, EXPLAIN_EVENT_END_FORMAT);
+        QRY_ERR_RET(nodesNodeToSQL(pEventNode->pEndCond, tbuf + VARSTR_HEADER_SIZE,
+                                    TSDB_EXPLAIN_RESULT_ROW_SIZE, &tlen));
+        EXPLAIN_ROW_END();
+        QRY_ERR_RET(qExplainResAppendRow(ctx, tbuf, tlen, level + 1));
+      }
+      break;
+    }
     default:
       qError("not supported physical node type %d", pNode->type);
       return TSDB_CODE_APP_ERROR;
diff --git a/source/libs/executor/inc/executorimpl.h b/source/libs/executor/inc/executorimpl.h
index c122a91d71..89c3b87b27 100644
--- a/source/libs/executor/inc/executorimpl.h
+++ b/source/libs/executor/inc/executorimpl.h
@@ -742,6 +742,7 @@ void appendOneRowToDataBlock(SSDataBlock* pBlock, STupleHandle* pTupleHandle);
 void setTbNameColData(const SSDataBlock* pBlock, SColumnInfoData* pColInfoData, int32_t functionId, const char* name);
 
 void setResultRowInitCtx(SResultRow* pResult, SqlFunctionCtx* pCtx, int32_t numOfOutput, int32_t* rowEntryInfoOffset);
+void clearResultRowInitFlag(SqlFunctionCtx* pCtx, int32_t numOfOutput);
 
 SResultRow* doSetResultOutBufByKey(SDiskbasedBuf* pResultBuf, SResultRowInfo* pResultRowInfo, char* pData,
                                    int16_t bytes, bool masterscan, uint64_t groupId, SExecTaskInfo* pTaskInfo,
@@ -813,6 +814,8 @@ SOperatorInfo* createStreamStateAggOperatorInfo(SOperatorInfo* downstream, SPhys
 SOperatorInfo* createStreamFillOperatorInfo(SOperatorInfo* downstream, SStreamFillPhysiNode* pPhyFillNode, SExecTaskInfo* pTaskInfo);
 
 SOperatorInfo* createGroupSortOperatorInfo(SOperatorInfo* downstream, SGroupSortPhysiNode* pSortPhyNode, SExecTaskInfo* pTaskInfo);
+
+SOperatorInfo* createEventwindowOperatorInfo(SOperatorInfo* downstream, SPhysiNode* physiNode, SExecTaskInfo* pTaskInfo);
 // clang-format on
 
 int32_t projectApplyFunctions(SExprInfo* pExpr, SSDataBlock* pResult, SSDataBlock* pSrcBlock, SqlFunctionCtx* pCtx,
@@ -872,6 +875,10 @@ void    appendCreateTableRow(SStreamState* pState, SExprSupp* pTableSup, SExprSu
 SSDataBlock* buildCreateTableBlock(SExprSupp* tbName, SExprSupp* tag);
 SExprInfo*   createExpr(SNodeList* pNodeList, int32_t* numOfExprs);
 
+void copyResultrowToDataBlock(SExprInfo* pExprInfo, int32_t numOfExprs, SResultRow* pRow, SqlFunctionCtx* pCtx,
+                             SSDataBlock* pBlock, const int32_t* rowEntryOffset, SExecTaskInfo* pTaskInfo);
+void doUpdateNumOfRows(SqlFunctionCtx* pCtx, SResultRow* pRow, int32_t numOfExprs, const int32_t* rowEntryOffset) ;
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/source/libs/executor/src/eventwindowoperator.c b/source/libs/executor/src/eventwindowoperator.c
new file mode 100644
index 0000000000..0e3c67c5d7
--- /dev/null
+++ b/source/libs/executor/src/eventwindowoperator.c
@@ -0,0 +1,338 @@
+/*
+ * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
+ *
+ * This program is free software: you can use, redistribute, and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3
+ * or later ("AGPL"), as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "executorimpl.h"
+#include "filter.h"
+#include "function.h"
+#include "functionMgt.h"
+#include "tcommon.h"
+#include "tcompare.h"
+#include "tdatablock.h"
+#include "ttime.h"
+
+typedef struct SEventWindowOperatorInfo {
+  SOptrBasicInfo     binfo;
+  SAggSupporter      aggSup;
+  SExprSupp          scalarSup;
+  SGroupResInfo      groupResInfo;
+  SWindowRowsSup     winSup;
+  bool               hasKey;
+  SStateKeys         stateKey;
+  int32_t            tsSlotId;  // primary timestamp column slot id
+  STimeWindowAggSupp twAggSup;
+
+  SFilterInfo* pStartCondInfo;
+  SFilterInfo* pEndCondInfo;
+  bool         inWindow;
+  SResultRow*  pRow;
+} SEventWindowOperatorInfo;
+
+static SSDataBlock* eventWindowAggregate(SOperatorInfo* pOperator);
+static void         destroyEWindowOperatorInfo(void* param);
+static void         eventWindowAggImpl(SOperatorInfo* pOperator, SEventWindowOperatorInfo* pInfo, SSDataBlock* pBlock);
+static SSDataBlock* doEventWindowAgg(SOperatorInfo* pOperator);
+
+// todo : move to  util
+static void doKeepNewWindowStartInfo(SWindowRowsSup* pRowSup, const int64_t* tsList, int32_t rowIndex,
+                                     uint64_t groupId) {
+  pRowSup->startRowIndex = rowIndex;
+  pRowSup->numOfRows = 0;
+  pRowSup->win.skey = tsList[rowIndex];
+  pRowSup->groupId = groupId;
+}
+
+static void doKeepTuple(SWindowRowsSup* pRowSup, int64_t ts, uint64_t groupId) {
+  pRowSup->win.ekey = ts;
+  pRowSup->prevTs = ts;
+  pRowSup->numOfRows += 1;
+  pRowSup->groupId = groupId;
+}
+
+static void updateTimeWindowInfo(SColumnInfoData* pColData, STimeWindow* pWin, bool includeEndpoint) {
+  int64_t* ts = (int64_t*)pColData->pData;
+  int32_t  delta = includeEndpoint ? 1 : 0;
+
+  int64_t duration = pWin->ekey - pWin->skey + delta;
+  ts[2] = duration;            // set the duration
+  ts[3] = pWin->skey;          // window start key
+  ts[4] = pWin->ekey + delta;  // window end key
+}
+
+SOperatorInfo* createEventwindowOperatorInfo(SOperatorInfo* downstream, SPhysiNode* physiNode,
+                                             SExecTaskInfo* pTaskInfo) {
+  SEventWindowOperatorInfo* pInfo = taosMemoryCalloc(1, sizeof(SEventWindowOperatorInfo));
+  SOperatorInfo*            pOperator = taosMemoryCalloc(1, sizeof(SOperatorInfo));
+  if (pInfo == NULL || pOperator == NULL) {
+    goto _error;
+  }
+
+  SEventWinodwPhysiNode* pEventWindowNode = (SEventWinodwPhysiNode*)physiNode;
+
+  int32_t tsSlotId = ((SColumnNode*)pEventWindowNode->window.pTspk)->slotId;
+  int32_t code = filterInitFromNode((SNode*)pEventWindowNode->pStartCond, &pInfo->pStartCondInfo, 0);
+  if (code != TSDB_CODE_SUCCESS) {
+    goto _error;
+  }
+
+  code = filterInitFromNode((SNode*)pEventWindowNode->pEndCond, &pInfo->pEndCondInfo, 0);
+  if (code != TSDB_CODE_SUCCESS) {
+    goto _error;
+  }
+
+  if (pEventWindowNode->window.pExprs != NULL) {
+    int32_t    numOfScalarExpr = 0;
+    SExprInfo* pScalarExprInfo = createExprInfo(pEventWindowNode->window.pExprs, NULL, &numOfScalarExpr);
+    code = initExprSupp(&pInfo->scalarSup, pScalarExprInfo, numOfScalarExpr);
+    if (code != TSDB_CODE_SUCCESS) {
+      goto _error;
+    }
+  }
+
+  code = filterInitFromNode((SNode*)pEventWindowNode->window.node.pConditions, &pOperator->exprSupp.pFilterInfo, 0);
+  if (code != TSDB_CODE_SUCCESS) {
+    goto _error;
+  }
+
+  size_t keyBufSize = sizeof(int64_t) + sizeof(int64_t) + POINTER_BYTES;
+
+  int32_t    num = 0;
+  SExprInfo* pExprInfo = createExprInfo(pEventWindowNode->window.pFuncs, NULL, &num);
+  initResultSizeInfo(&pOperator->resultInfo, 4096);
+
+  code = initAggSup(&pOperator->exprSupp, &pInfo->aggSup, pExprInfo, num, keyBufSize, pTaskInfo->id.str,
+                    pTaskInfo->streamInfo.pState);
+  if (code != TSDB_CODE_SUCCESS) {
+    goto _error;
+  }
+
+  SSDataBlock* pResBlock = createDataBlockFromDescNode(pEventWindowNode->window.node.pOutputDataBlockDesc);
+  blockDataEnsureCapacity(pResBlock, pOperator->resultInfo.capacity);
+
+  initBasicInfo(&pInfo->binfo, pResBlock);
+  initResultRowInfo(&pInfo->binfo.resultRowInfo);
+
+  pInfo->twAggSup = (STimeWindowAggSupp){.waterMark = pEventWindowNode->window.watermark,
+                                         .calTrigger = pEventWindowNode->window.triggerType};
+
+  initExecTimeWindowInfo(&pInfo->twAggSup.timeWindowData, &pTaskInfo->window);
+
+  pInfo->tsSlotId = tsSlotId;
+
+  setOperatorInfo(pOperator, "EventWindowOperator", QUERY_NODE_PHYSICAL_PLAN_MERGE_STATE, true, OP_NOT_OPENED, pInfo,
+                  pTaskInfo);
+  pOperator->fpSet = createOperatorFpSet(optrDummyOpenFn, eventWindowAggregate, NULL, destroyEWindowOperatorInfo,
+                                         optrDefaultBufFn, NULL);
+
+  code = appendDownstream(pOperator, &downstream, 1);
+  if (code != TSDB_CODE_SUCCESS) {
+    goto _error;
+  }
+
+  return pOperator;
+
+_error:
+  if (pInfo != NULL) {
+    destroyEWindowOperatorInfo(pInfo);
+  }
+
+  taosMemoryFreeClear(pOperator);
+  pTaskInfo->code = code;
+  return NULL;
+}
+
+void destroyEWindowOperatorInfo(void* param) {
+  SEventWindowOperatorInfo* pInfo = (SEventWindowOperatorInfo*)param;
+  if (pInfo == NULL) {
+    return;
+  }
+
+  if (pInfo->pRow != NULL) {
+    taosMemoryFree(pInfo->pRow);
+  }
+
+  if (pInfo->pStartCondInfo != NULL) {
+    filterFreeInfo(pInfo->pStartCondInfo);
+    pInfo->pStartCondInfo = NULL;
+  }
+
+  if (pInfo->pEndCondInfo != NULL) {
+    filterFreeInfo(pInfo->pEndCondInfo);
+    pInfo->pEndCondInfo = NULL;
+  }
+
+  cleanupBasicInfo(&pInfo->binfo);
+  colDataDestroy(&pInfo->twAggSup.timeWindowData);
+
+  cleanupAggSup(&pInfo->aggSup);
+  cleanupGroupResInfo(&pInfo->groupResInfo);
+  taosMemoryFreeClear(param);
+}
+
+static SSDataBlock* eventWindowAggregate(SOperatorInfo* pOperator) {
+  SEventWindowOperatorInfo* pInfo = pOperator->info;
+  SExecTaskInfo*            pTaskInfo = pOperator->pTaskInfo;
+
+  SExprSupp* pSup = &pOperator->exprSupp;
+  int32_t    order = TSDB_ORDER_ASC;
+
+  SSDataBlock* pRes = pInfo->binfo.pRes;
+
+  blockDataCleanup(pRes);
+
+  SOperatorInfo* downstream = pOperator->pDownstream[0];
+  while (1) {
+    SSDataBlock* pBlock = downstream->fpSet.getNextFn(downstream);
+    if (pBlock == NULL) {
+      break;
+    }
+
+    setInputDataBlock(pSup, pBlock, order, MAIN_SCAN, true);
+    blockDataUpdateTsWindow(pBlock, pInfo->tsSlotId);
+
+    // there is an scalar expression that needs to be calculated right before apply the group aggregation.
+    if (pInfo->scalarSup.pExprInfo != NULL) {
+      pTaskInfo->code = projectApplyFunctions(pInfo->scalarSup.pExprInfo, pBlock, pBlock, pInfo->scalarSup.pCtx,
+                                              pInfo->scalarSup.numOfExprs, NULL);
+      if (pTaskInfo->code != TSDB_CODE_SUCCESS) {
+        T_LONG_JMP(pTaskInfo->env, pTaskInfo->code);
+      }
+    }
+
+    eventWindowAggImpl(pOperator, pInfo, pBlock);
+    if (pRes->info.rows >= pOperator->resultInfo.threshold) {
+      return pRes;
+    }
+  }
+
+  return pRes->info.rows == 0 ? NULL : pRes;
+}
+
+static int32_t setSingleOutputTupleBufv1(SResultRowInfo* pResultRowInfo, STimeWindow* win, SResultRow** pResult,
+                                         SExprSupp* pExprSup, SAggSupporter* pAggSup) {
+  if (*pResult == NULL) {
+    SResultRow* p = taosMemoryCalloc(1, pAggSup->resultRowSize);
+    pResultRowInfo->cur = (SResultRowPosition){.pageId = p->pageId, .offset = p->offset};
+    *pResult = p;
+  }
+
+  (*pResult)->win = *win;
+
+  clearResultRowInitFlag(pExprSup->pCtx, pExprSup->numOfExprs);
+  setResultRowInitCtx(*pResult, pExprSup->pCtx, pExprSup->numOfExprs, pExprSup->rowEntryInfoOffset);
+  return TSDB_CODE_SUCCESS;
+}
+
+static void doEventWindowAggImpl(SEventWindowOperatorInfo* pInfo, SExprSupp* pSup, int32_t startIndex, int32_t endIndex,
+                                 const SSDataBlock* pBlock, int64_t* tsList, SExecTaskInfo* pTaskInfo) {
+  SWindowRowsSup* pRowSup = &pInfo->winSup;
+
+  int32_t numOfOutput = pSup->numOfExprs;
+  int32_t numOfRows = endIndex - startIndex + 1;
+
+  doKeepTuple(pRowSup, tsList[endIndex], pBlock->info.id.groupId);
+
+  int32_t ret =
+      setSingleOutputTupleBufv1(&pInfo->binfo.resultRowInfo, &pRowSup->win, &pInfo->pRow, pSup, &pInfo->aggSup);
+  if (ret != TSDB_CODE_SUCCESS) {  // null data, too many state code
+    T_LONG_JMP(pTaskInfo->env, TSDB_CODE_APP_ERROR);
+  }
+
+  updateTimeWindowInfo(&pInfo->twAggSup.timeWindowData, &pRowSup->win, false);
+  applyAggFunctionOnPartialTuples(pTaskInfo, pSup->pCtx, &pInfo->twAggSup.timeWindowData, startIndex, numOfRows,
+                                  pBlock->info.rows, numOfOutput);
+}
+
+void eventWindowAggImpl(SOperatorInfo* pOperator, SEventWindowOperatorInfo* pInfo, SSDataBlock* pBlock) {
+  SExecTaskInfo* pTaskInfo = pOperator->pTaskInfo;
+  SExprSupp*     pSup = &pOperator->exprSupp;
+
+  SSDataBlock* pRes = pInfo->binfo.pRes;
+  int64_t      gid = pBlock->info.id.groupId;
+
+  SColumnInfoData* pColInfoData = taosArrayGet(pBlock->pDataBlock, pInfo->tsSlotId);
+  TSKEY*           tsList = (TSKEY*)pColInfoData->pData;
+
+  SColumnInfoData *ps = NULL, *pe = NULL;
+
+  SWindowRowsSup* pRowSup = &pInfo->winSup;
+  pRowSup->numOfRows = 0;
+
+  SFilterColumnParam param1 = {.numOfCols = taosArrayGetSize(pBlock->pDataBlock), .pDataBlock = pBlock->pDataBlock};
+  int32_t            code = filterSetDataFromSlotId(pInfo->pStartCondInfo, &param1);
+
+  int32_t status1 = 0;
+  bool    keep1 = filterExecute(pInfo->pStartCondInfo, pBlock, &ps, NULL, param1.numOfCols, &status1);
+
+  SFilterColumnParam param2 = {.numOfCols = taosArrayGetSize(pBlock->pDataBlock), .pDataBlock = pBlock->pDataBlock};
+  code = filterSetDataFromSlotId(pInfo->pEndCondInfo, &param2);
+
+  int32_t status2 = 0;
+  bool    keep2 = filterExecute(pInfo->pEndCondInfo, pBlock, &pe, NULL, param2.numOfCols, &status2);
+
+  int32_t rowIndex = 0;
+  int32_t startIndex = pInfo->inWindow ? 0 : -1;
+
+  while (rowIndex < pBlock->info.rows) {
+    if (pInfo->inWindow) {  // let's find the first end value
+      for (rowIndex = startIndex; rowIndex < pBlock->info.rows; ++rowIndex) {
+        if (((bool*)pe->pData)[rowIndex]) {
+          break;
+        }
+      }
+
+      if (rowIndex < pBlock->info.rows) {
+        doEventWindowAggImpl(pInfo, pSup, startIndex, rowIndex, pBlock, tsList, pTaskInfo);
+
+        doUpdateNumOfRows(pSup->pCtx, pInfo->pRow, pSup->numOfExprs, pSup->rowEntryInfoOffset);
+
+        // check buffer size
+        if (pRes->info.rows + pInfo->pRow->numOfRows >= pRes->info.capacity) {
+          int32_t newSize = pRes->info.rows + pInfo->pRow->numOfRows;
+          blockDataEnsureCapacity(pRes, newSize);
+        }
+
+        copyResultrowToDataBlock(pSup->pExprInfo, pSup->numOfExprs, pInfo->pRow, pSup->pCtx, pRes,
+                                 pSup->rowEntryInfoOffset, pTaskInfo);
+
+        pRes->info.rows += pInfo->pRow->numOfRows;
+
+        pInfo->inWindow = false;
+        rowIndex += 1;
+      } else {
+        doEventWindowAggImpl(pInfo, pSup, startIndex, pBlock->info.rows - 1, pBlock, tsList, pTaskInfo);
+      }
+    } else {  // find the first start value that is fulfill for the start condition
+      for (; rowIndex < pBlock->info.rows; ++rowIndex) {
+        if (((bool*)ps->pData)[rowIndex]) {
+          doKeepNewWindowStartInfo(pRowSup, tsList, rowIndex, gid);
+          pInfo->inWindow = true;
+          startIndex = rowIndex;
+          break;
+        }
+      }
+
+      if (pInfo->inWindow) {
+        continue;
+      } else {
+        break;
+      }
+    }
+  }
+
+  colDataDestroy(ps);
+  taosMemoryFree(ps);
+  colDataDestroy(pe);
+  taosMemoryFree(pe);
+}
diff --git a/source/libs/executor/src/executorimpl.c b/source/libs/executor/src/executorimpl.c
index c7ea27edad..21ef5dfab3 100644
--- a/source/libs/executor/src/executorimpl.c
+++ b/source/libs/executor/src/executorimpl.c
@@ -833,6 +833,20 @@ void setResultRowInitCtx(SResultRow* pResult, SqlFunctionCtx* pCtx, int32_t numO
   }
 }
 
+void clearResultRowInitFlag(SqlFunctionCtx* pCtx, int32_t numOfOutput) {
+  for (int32_t i = 0; i < numOfOutput; ++i) {
+    SResultRowEntryInfo* pResInfo = pCtx[i].resultInfo;
+    if (pResInfo == NULL) {
+      continue;
+    }
+
+    pResInfo->initialized = false;
+    pResInfo->numOfRes = 0;
+    pResInfo->isNullRes = 0;
+    pResInfo->complete = false;
+  }
+}
+
 void doFilter(SSDataBlock* pBlock, SFilterInfo* pFilterInfo, SColMatchInfo* pColMatchInfo) {
   if (pFilterInfo == NULL || pBlock->info.rows == 0) {
     return;
@@ -892,12 +906,11 @@ void extractQualifiedTupleByFilterResult(SSDataBlock* pBlock, const SColumnInfoD
       }
 
       int32_t numOfRows = 0;
-
       if (IS_VAR_DATA_TYPE(pDst->info.type)) {
         int32_t j = 0;
         pDst->varmeta.length = 0;
 
-        while(j < totalRows) {
+        while (j < totalRows) {
           if (pIndicator[j] == 0) {
             j += 1;
             continue;
@@ -1050,8 +1063,7 @@ static void setExecutionContext(SOperatorInfo* pOperator, int32_t numOfOutput, u
   pAggInfo->groupId = groupId;
 }
 
-static void doUpdateNumOfRows(SqlFunctionCtx* pCtx, SResultRow* pRow, int32_t numOfExprs,
-                              const int32_t* rowEntryOffset) {
+void doUpdateNumOfRows(SqlFunctionCtx* pCtx, SResultRow* pRow, int32_t numOfExprs, const int32_t* rowEntryOffset) {
   bool returnNotNull = false;
   for (int32_t j = 0; j < numOfExprs; ++j) {
     SResultRowEntryInfo* pResInfo = getResultEntryInfo(pRow, j, rowEntryOffset);
@@ -1074,8 +1086,8 @@ static void doUpdateNumOfRows(SqlFunctionCtx* pCtx, SResultRow* pRow, int32_t nu
   }
 }
 
-static void doCopyResultToDataBlock(SExprInfo* pExprInfo, int32_t numOfExprs, SResultRow* pRow, SqlFunctionCtx* pCtx,
-                                    SSDataBlock* pBlock, const int32_t* rowEntryOffset, SExecTaskInfo* pTaskInfo) {
+void copyResultrowToDataBlock(SExprInfo* pExprInfo, int32_t numOfExprs, SResultRow* pRow, SqlFunctionCtx* pCtx,
+                              SSDataBlock* pBlock, const int32_t* rowEntryOffset, SExecTaskInfo* pTaskInfo) {
   for (int32_t j = 0; j < numOfExprs; ++j) {
     int32_t slotId = pExprInfo[j].base.resSchema.slotId;
 
@@ -1111,7 +1123,7 @@ static void doCopyResultToDataBlock(SExprInfo* pExprInfo, int32_t numOfExprs, SR
 // todo refactor. SResultRow has direct pointer in miainfo
 int32_t finalizeResultRows(SDiskbasedBuf* pBuf, SResultRowPosition* resultRowPosition, SExprSupp* pSup,
                            SSDataBlock* pBlock, SExecTaskInfo* pTaskInfo) {
-  SFilePage*  page = getBufPage(pBuf, resultRowPosition->pageId);
+  SFilePage* page = getBufPage(pBuf, resultRowPosition->pageId);
   if (page == NULL) {
     qError("failed to get buffer, code:%s, %s", tstrerror(terrno), GET_TASKID(pTaskInfo));
     T_LONG_JMP(pTaskInfo->env, terrno);
@@ -1141,7 +1153,7 @@ int32_t finalizeResultRows(SDiskbasedBuf* pBuf, SResultRowPosition* resultRowPos
     T_LONG_JMP(pTaskInfo->env, code);
   }
 
-  doCopyResultToDataBlock(pExprInfo, pSup->numOfExprs, pRow, pCtx, pBlock, rowEntryOffset, pTaskInfo);
+  copyResultrowToDataBlock(pExprInfo, pSup->numOfExprs, pRow, pCtx, pBlock, rowEntryOffset, pTaskInfo);
 
   releaseBufPage(pBuf, page);
   pBlock->info.rows += pRow->numOfRows;
@@ -1193,7 +1205,7 @@ int32_t doCopyToSDataBlock(SExecTaskInfo* pTaskInfo, SSDataBlock* pBlock, SExprS
     }
 
     pGroupResInfo->index += 1;
-    doCopyResultToDataBlock(pExprInfo, numOfExprs, pRow, pCtx, pBlock, rowEntryOffset, pTaskInfo);
+    copyResultrowToDataBlock(pExprInfo, numOfExprs, pRow, pCtx, pBlock, rowEntryOffset, pTaskInfo);
 
     releaseBufPage(pBuf, page);
     pBlock->info.rows += pRow->numOfRows;
@@ -2222,8 +2234,6 @@ SOperatorInfo* createOperatorTree(SPhysiNode* pPhyNode, SExecTaskInfo* pTaskInfo
       pOperator = createCacherowsScanOperator(pScanNode, pHandle, pTaskInfo);
     } else if (QUERY_NODE_PHYSICAL_PLAN_PROJECT == type) {
       pOperator = createProjectOperatorInfo(NULL, (SProjectPhysiNode*)pPhyNode, pTaskInfo);
-    } else {
-      ASSERT(0);
     }
 
     if (pOperator != NULL) {
@@ -2312,8 +2322,8 @@ SOperatorInfo* createOperatorTree(SPhysiNode* pPhyNode, SExecTaskInfo* pTaskInfo
     pOptr = createIndefinitOutputOperatorInfo(ops[0], pPhyNode, pTaskInfo);
   } else if (QUERY_NODE_PHYSICAL_PLAN_INTERP_FUNC == type) {
     pOptr = createTimeSliceOperatorInfo(ops[0], pPhyNode, pTaskInfo);
-  } else {
-    ASSERT(0);
+  } else if (QUERY_NODE_PHYSICAL_PLAN_MERGE_EVENT == type) {
+    pOptr = createEventwindowOperatorInfo(ops[0], pPhyNode, pTaskInfo);
   }
 
   taosMemoryFree(ops);
diff --git a/source/libs/executor/src/timewindowoperator.c b/source/libs/executor/src/timewindowoperator.c
index 68f178803d..eccdcb85bf 100644
--- a/source/libs/executor/src/timewindowoperator.c
+++ b/source/libs/executor/src/timewindowoperator.c
@@ -1973,6 +1973,7 @@ static SSDataBlock* doSessionWindowAgg(SOperatorInfo* pOperator) {
   return (pBInfo->pRes->info.rows == 0) ? NULL : pBInfo->pRes;
 }
 
+// todo make this as an non-blocking operator
 SOperatorInfo* createStatewindowOperatorInfo(SOperatorInfo* downstream, SStateWinodwPhysiNode* pStateNode,
                                              SExecTaskInfo* pTaskInfo) {
   SStateWindowOperatorInfo* pInfo = taosMemoryCalloc(1, sizeof(SStateWindowOperatorInfo));
diff --git a/tests/script/tsim/query/event.sim b/tests/script/tsim/query/event.sim
new file mode 100644
index 0000000000..adc94a34de
--- /dev/null
+++ b/tests/script/tsim/query/event.sim
@@ -0,0 +1,69 @@
+system sh/stop_dnodes.sh
+system sh/deploy.sh -n dnode1 -i 1
+system sh/exec.sh -n dnode1 -s start
+sql connect
+
+print ======== prepare data 
+
+sql drop database if exists db1;
+sql create database db1 vgroups 5;
+sql use db1;
+sql create stable sta (ts timestamp, f1 int, f2 binary(10), f3 bool) tags(t1 int, t2 bool, t3 binary(10));
+sql create table tba1 using sta tags(0, false, '0');
+sql create table tba2 using sta tags(1, true, '1');
+sql create table tba3 using sta tags(null, null, '');
+sql create table tba4 using sta tags(1, false, null);
+sql create table tba5 using sta tags(3, true, 'aa');
+sql insert into tba1 values ('2022-09-26 15:15:01', 0, "a", false);
+sql insert into tba1 values ('2022-09-26 15:15:02', 1, "0", true);
+sql insert into tba1 values ('2022-09-26 15:15:03', 5, "5", false);
+sql insert into tba1 values ('2022-09-26 15:15:04', 3, 'b', false);
+sql insert into tba1 values ('2022-09-26 15:15:05', 0, '1', false);
+sql insert into tba1 values ('2022-09-26 15:15:06', 2, 'd', true);
+
+sql insert into tba2 values ('2022-09-27 15:15:01', 0, "a", false);
+sql insert into tba2 values ('2022-09-27 15:15:02', 1, "0", true);
+sql insert into tba2 values ('2022-09-27 15:15:03', 5, "5", false);
+sql insert into tba2 values ('2022-09-27 15:15:04', null, null, null);
+
+# child table: no window
+print ====> select count(*) from tba1 event_window start with f1 = 0 end with f2 = 'c';
+sql select count(*) from tba1 event_window start with f1 = 0 end with f2 = 'c';
+if $rows != 0 then
+  return -1
+endi
+
+# child table: single row window
+print ====> select count(*) from tba1 event_window start with f1 = 0 end with f3 = false;
+sql select count(*) from tba1 event_window start with f1 = 0 end with f3 = false
+if $rows != 2 then
+  return -1
+endi
+if $data00 != 1 then
+  return -1
+endi
+
+# child table: multi rows window
+print ====> select count(*) from tba1 event_window start with f1 = 0 end with f2 = 'b';
+sql select count(*) from tba1 event_window start with f1 = 0 end with f2 = 'b';
+if $rows != 1 then
+  return -1
+endi
+if $data00 != 4 then
+  return -1
+endi
+
+# child table: multi windows
+print ====> select count(*) from tba1 event_window start with f1 >= 0 end with f3 = true;
+sql select count(*) from tba1 event_window start with f1 >= 0 end with f3 = true;
+if $rows != 2 then
+  return -1
+endi
+if $data00 != 2 then
+  return -1
+endi
+if $data10 != 4 then
+  return -1
+endi
+
+system sh/exec.sh -n dnode1 -s stop -x SIGINT