Merge pull request #2784 from taosdata/feature/query

Feature/query

src/client/inc/tsclient.h

@@ -31,8 +31,8 @@ extern "C" {
 #include "tutil.h"
 
 #include "qExecutor.h"
+#include "qSqlparser.h"
 #include "qTsbuf.h"
-#include "qsqlparser.h"
 #include "tcmdtype.h"
 
 // forward declaration

src/client/src/tscAsync.c

@@ -430,7 +430,7 @@ void tscTableMetaCallBack(void *param, TAOS_RES *res, int code) {
   pRes->code = code;
 
   if (code != TSDB_CODE_SUCCESS) {
-    tscError("%p ge tableMeta failed, code:%s", pSql, tstrerror(code));
+    tscError("%p get tableMeta failed, code:%s", pSql, tstrerror(code));
     goto _error;
   } else {
     tscDebug("%p get tableMeta successfully", pSql);

src/client/src/tscFunctionImpl.c

@@ -2131,6 +2131,11 @@ static STopBotInfo *getTopBotOutputInfo(SQLFunctionCtx *pCtx) {
 }
 
 bool topbot_datablock_filter(SQLFunctionCtx *pCtx, int32_t functionId, const char *minval, const char *maxval) {
+  SResultInfo *pResInfo = GET_RES_INFO(pCtx);
+  if (pResInfo == NULL) {
+    return true;
+  }
+
   STopBotInfo *pTopBotInfo = getTopBotOutputInfo(pCtx);
   
   // required number of results are not reached, continue load data block

src/client/src/tscLocalMerge.c

@@ -691,9 +691,15 @@ int32_t tscLocalReducerEnvCreate(SSqlObj *pSql, tExtMemBuffer ***pMemBuffer, tOr
   
   pModel = createColumnModel(pSchema, size, capacity);
 
+  int32_t pg = DEFAULT_PAGE_SIZE;
+  int32_t overhead = sizeof(tFilePage);
+  while((pg - overhead) < pModel->rowSize * 2) {
+    pg *= 2;
+  }
+
   size_t numOfSubs = pTableMetaInfo->vgroupList->numOfVgroups;
   for (int32_t i = 0; i < numOfSubs; ++i) {
-    (*pMemBuffer)[i] = createExtMemBuffer(nBufferSizes, rlen, pModel);
+    (*pMemBuffer)[i] = createExtMemBuffer(nBufferSizes, rlen, pg, pModel);
     (*pMemBuffer)[i]->flushModel = MULTIPLE_APPEND_MODEL;
   }
 

src/client/src/tscSubquery.c

@@ -1505,12 +1505,11 @@ static int32_t tscReissueSubquery(SRetrieveSupport *trsupport, SSqlObj *pSql, in
 
   SSqlObj *pNew = tscCreateSqlObjForSubquery(trsupport->pParentSql, trsupport, pSql);
 
-  // todo add to async res or not??
   if (pNew == NULL) {
-    tscError("%p sub:%p failed to create new subquery due to out of memory, abort retry, vgId:%d, orderOfSub:%d",
-             trsupport->pParentSql, pSql, pVgroup->vgId, trsupport->subqueryIndex);
+    tscError("%p sub:%p failed to create new subquery due to error:%s, abort retry, vgId:%d, orderOfSub:%d",
+             trsupport->pParentSql, pSql, tstrerror(terrno), pVgroup->vgId, trsupport->subqueryIndex);
 
-    pParentSql->res.code = TSDB_CODE_TSC_OUT_OF_MEMORY;
+    pParentSql->res.code = terrno;
     trsupport->numOfRetry = MAX_NUM_OF_SUBQUERY_RETRY;
 
     return pParentSql->res.code;

src/client/src/tscSystem.c

@@ -148,7 +148,7 @@ void taos_init_imp() {
   refreshTime = refreshTime < 10 ? 10 : refreshTime;
 
   if (tscCacheHandle == NULL) {
-    tscCacheHandle = taosCacheInit(TSDB_DATA_TYPE_BINARY, refreshTime, false, NULL, "client");
+    tscCacheHandle = taosCacheInit(TSDB_DATA_TYPE_BINARY, refreshTime, false, NULL, "tableMeta");
   }
 
   tscDebug("client is initialized successfully");

src/client/src/tscUtil.c

@@ -356,9 +356,9 @@ void tscPartiallyFreeSqlObj(SSqlObj* pSql) {
   
   // pSql->sqlstr will be used by tscBuildQueryStreamDesc
   if (pObj->signature == pObj) {
-    pthread_mutex_lock(&pObj->mutex);
+    //pthread_mutex_lock(&pObj->mutex);
     tfree(pSql->sqlstr);
-    pthread_mutex_unlock(&pObj->mutex);
+    //pthread_mutex_unlock(&pObj->mutex);
   }
   
   tscFreeSqlResult(pSql);
@@ -1675,6 +1675,7 @@ SSqlObj* createSubqueryObj(SSqlObj* pSql, int16_t tableIndex, void (*fp)(), void
   SSqlObj* pNew = (SSqlObj*)calloc(1, sizeof(SSqlObj));
   if (pNew == NULL) {
     tscError("%p new subquery failed, tableIndex:%d", pSql, tableIndex);
+    terrno = TSDB_CODE_TSC_OUT_OF_MEMORY;
     return NULL;
   }
   
@@ -1688,6 +1689,7 @@ SSqlObj* createSubqueryObj(SSqlObj* pSql, int16_t tableIndex, void (*fp)(), void
     tscError("%p new subquery failed, tableIndex:%d, vgroupIndex:%d", pSql, tableIndex, pTableMetaInfo->vgroupIndex);
 
     free(pNew);
+    terrno = TSDB_CODE_TSC_OUT_OF_MEMORY;
     return NULL;
   }
 
@@ -1706,6 +1708,7 @@ SSqlObj* createSubqueryObj(SSqlObj* pSql, int16_t tableIndex, void (*fp)(), void
 
   if (tscAddSubqueryInfo(pnCmd) != TSDB_CODE_SUCCESS) {
     tscFreeSqlObj(pNew);
+    terrno = TSDB_CODE_TSC_OUT_OF_MEMORY;
     return NULL;
   }
 
@@ -1743,6 +1746,7 @@ SSqlObj* createSubqueryObj(SSqlObj* pSql, int16_t tableIndex, void (*fp)(), void
   if (tscAllocPayload(pnCmd, TSDB_DEFAULT_PAYLOAD_SIZE) != TSDB_CODE_SUCCESS) {
     tscError("%p new subquery failed, tableIndex:%d, vgroupIndex:%d", pSql, tableIndex, pTableMetaInfo->vgroupIndex);
     tscFreeSqlObj(pNew);
+    terrno = TSDB_CODE_TSC_OUT_OF_MEMORY;
     return NULL;
   }
   
@@ -1827,8 +1831,16 @@ SSqlObj* createSubqueryObj(SSqlObj* pSql, int16_t tableIndex, void (*fp)(), void
   }
 
   if (pFinalInfo->pTableMeta == NULL) {
-    tscError("%p new subquery failed for get tableMeta is NULL from cache", pSql);
+    tscError("%p new subquery failed since no tableMeta in cache, name:%s", pSql, name);
     tscFreeSqlObj(pNew);
+
+    if (pPrevSql != NULL) {
+      assert(pPrevSql->res.code != TSDB_CODE_SUCCESS);
+      terrno = pPrevSql->res.code;
+    } else {
+      terrno = TSDB_CODE_TSC_APP_ERROR;
+    }
+
     return NULL;
   }
   

src/dnode/src/dnodeVRead.c

@@ -49,7 +49,7 @@ static taos_qset       readQset;
 int32_t dnodeInitVnodeRead() {
   readQset = taosOpenQset();
 
-  readPool.min = 2;
+  readPool.min = tsNumOfCores;
   readPool.max = tsNumOfCores * tsNumOfThreadsPerCore;
   if (readPool.max <= readPool.min * 2) readPool.max = 2 * readPool.min;
   readPool.readWorker = (SReadWorker *)calloc(sizeof(SReadWorker), readPool.max);
@@ -206,10 +206,14 @@ static void *dnodeProcessReadQueue(void *param) {
            taosMsg[pReadMsg->rpcMsg.msgType], type);
     int32_t code = vnodeProcessRead(pVnode, pReadMsg);
 
-    if (type == TAOS_QTYPE_RPC) {
+    if (type == TAOS_QTYPE_RPC && code != TSDB_CODE_QRY_NOT_READY) {
       dnodeSendRpcReadRsp(pVnode, pReadMsg, code);
     } else {
-      dnodeDispatchNonRspMsg(pVnode, pReadMsg, code);
+      if (code == TSDB_CODE_QRY_HAS_RSP) {
+        dnodeSendRpcReadRsp(pVnode, pReadMsg, TSDB_CODE_SUCCESS);
+      } else {
+        dnodeDispatchNonRspMsg(pVnode, pReadMsg, code);
+      }
     }
 
     taosFreeQitem(pReadMsg);

src/inc/query.h

@@ -28,7 +28,7 @@ typedef void* qinfo_t;
  * @param qinfo
  * @return
  */
-int32_t qCreateQueryInfo(void* tsdb, int32_t vgId, SQueryTableMsg* pQueryTableMsg, void* param, qinfo_t* qinfo);
+int32_t qCreateQueryInfo(void* tsdb, int32_t vgId, SQueryTableMsg* pQueryTableMsg, qinfo_t* qinfo);
 
 
 /**
@@ -38,7 +38,10 @@ int32_t qCreateQueryInfo(void* tsdb, int32_t vgId, SQueryTableMsg* pQueryTableMs
  * @param qinfo
  * @return
  */
-void qTableQuery(qinfo_t qinfo);
+bool qTableQuery(qinfo_t qinfo);
+
+void* pGetRspMsg(qinfo_t qinfo);
+
 
 /**
  * Retrieve the produced results information, if current query is not paused or completed,
@@ -48,7 +51,7 @@ void qTableQuery(qinfo_t qinfo);
  * @param qinfo
  * @return
  */
-int32_t qRetrieveQueryResultInfo(qinfo_t qinfo);
+int32_t qRetrieveQueryResultInfo(qinfo_t qinfo, bool* buildRes, void* pRspContext);
 
 /**
  *
@@ -60,16 +63,9 @@ int32_t qRetrieveQueryResultInfo(qinfo_t qinfo);
  * @param contLen payload length
  * @return
  */
-int32_t qDumpRetrieveResult(qinfo_t qinfo, SRetrieveTableRsp** pRsp, int32_t* contLen);
+int32_t qDumpRetrieveResult(qinfo_t qinfo, SRetrieveTableRsp** pRsp, int32_t* contLen, bool* continueExec);
 
-/**
- * Decide if more results will be produced or not, NOTE: this function will increase the ref count of QInfo,
- * so it can be only called once for each retrieve
- *
- * @param qinfo
- * @return
- */
-bool qHasMoreResultsToRetrieve(qinfo_t qinfo);
+void* qGetResultRetrieveMsg(qinfo_t qinfo);
 
 /**
  * kill current ongoing query and free query handle automatically

src/inc/taoserror.h

@@ -216,6 +216,8 @@ TAOS_DEFINE_ERROR(TSDB_CODE_QRY_OUT_OF_MEMORY,            0, 0x0703, "query out
 TAOS_DEFINE_ERROR(TSDB_CODE_QRY_APP_ERROR,                0, 0x0704, "query app error")
 TAOS_DEFINE_ERROR(TSDB_CODE_QRY_DUP_JOIN_KEY,             0, 0x0705, "query duplicated join key")
 TAOS_DEFINE_ERROR(TSDB_CODE_QRY_EXCEED_TAGS_LIMIT,        0, 0x0706, "query tag conditon too many")
+TAOS_DEFINE_ERROR(TSDB_CODE_QRY_NOT_READY,                0, 0x0707, "query not ready")
+TAOS_DEFINE_ERROR(TSDB_CODE_QRY_HAS_RSP,                  0, 0x0708, "query should response")
 
 // grant
 TAOS_DEFINE_ERROR(TSDB_CODE_GRANT_EXPIRED,                0, 0x0800, "grant expired")

src/mnode/src/mnodeProfile.c

@@ -68,7 +68,7 @@ int32_t mnodeInitProfile() {
   mnodeAddWriteMsgHandle(TSDB_MSG_TYPE_CM_KILL_STREAM, mnodeProcessKillStreamMsg);
   mnodeAddWriteMsgHandle(TSDB_MSG_TYPE_CM_KILL_CONN, mnodeProcessKillConnectionMsg);
 
-  tsMnodeConnCache = taosCacheInit(TSDB_DATA_TYPE_INT, CONN_CHECK_TIME, false, mnodeFreeConn, "conn");
+  tsMnodeConnCache = taosCacheInit(TSDB_DATA_TYPE_INT, CONN_CHECK_TIME, true, mnodeFreeConn, "conn");
   return 0;
 }
 
@@ -119,7 +119,7 @@ SConnObj *mnodeAccquireConn(int32_t connId, char *user, uint32_t ip, uint16_t po
     return NULL;
   }
 
-  if (pConn->ip != ip || pConn->port != port /* || strcmp(pConn->user, user) != 0 */) {
+  if (/* pConn->ip != ip || */ pConn->port != port /* || strcmp(pConn->user, user) != 0 */) {
     mError("connId:%d, incoming conn user:%s ip:%s:%u, not match exist conn user:%s ip:%s:%u", connId, user,
            taosIpStr(ip), port, pConn->user, taosIpStr(pConn->ip), pConn->port);
     taosCacheRelease(tsMnodeConnCache, (void **)&pConn, false);

src/plugins/http/src/httpContext.c

@@ -58,7 +58,7 @@ static void httpDestroyContext(void *data) {
 }
 
 bool httpInitContexts() {
-  tsHttpServer.contextCache = taosCacheInit(TSDB_DATA_TYPE_BIGINT, 2, false, httpDestroyContext, "restc");
+  tsHttpServer.contextCache = taosCacheInit(TSDB_DATA_TYPE_BIGINT, 2, true, httpDestroyContext, "restc");
   if (tsHttpServer.contextCache == NULL) {
     httpError("failed to init context cache");
     return false;

src/query/inc/qExecutor.h

@@ -20,8 +20,8 @@
 #include "hash.h"
 #include "qFill.h"
 #include "qResultbuf.h"
+#include "qSqlparser.h"
 #include "qTsbuf.h"
-#include "qsqlparser.h"
 #include "query.h"
 #include "taosdef.h"
 #include "tarray.h"
@@ -43,7 +43,7 @@ typedef struct SSqlGroupbyExpr {
 
 typedef struct SPosInfo {
   int32_t pageId;
-  int16_t rowId;
+  int32_t rowId;
 } SPosInfo;
 
 typedef struct SWindowStatus {
@@ -177,13 +177,18 @@ typedef struct SQueryRuntimeEnv {
   SDiskbasedResultBuf* pResultBuf;       // query result buffer based on blocked-wised disk file
 } SQueryRuntimeEnv;
 
+enum {
+  QUERY_RESULT_NOT_READY = 1,
+  QUERY_RESULT_READY     = 2,
+};
+
 typedef struct SQInfo {
   void*            signature;
   int32_t          pointsInterpo;
   int32_t          code;  // error code to returned to client
-  sem_t            dataReady;
+//  sem_t            dataReady;
+
   void*            tsdb;
-  void*            param;
   int32_t          vgId;
   STableGroupInfo  tableGroupInfo;       // table id list < only includes the STable list>
   STableGroupInfo  tableqinfoGroupInfo;  // this is a group array list, including SArray<STableQueryInfo*> structure
@@ -200,8 +205,11 @@ typedef struct SQInfo {
    */
   int32_t          tableIndex;
   int32_t          numOfGroupResultPages;
-  void*            pBuf; // allocated buffer for STableQueryInfo, sizeof(STableQueryInfo)*numOfTables;
+  void*            pBuf;        // allocated buffer for STableQueryInfo, sizeof(STableQueryInfo)*numOfTables;
 
+  pthread_mutex_t  lock;        // used to synchronize the rsp/query threads
+  int32_t          dataReady;   // denote if query result is ready or not
+  void*            rspContext;  // response context
 } SQInfo;
 
 #endif  // TDENGINE_QUERYEXECUTOR_H

src/query/inc/qExtbuffer.h

@@ -19,7 +19,6 @@
 extern "C" {
 #endif
 
-
 #include "os.h"
 #include "taosmsg.h"
 
@@ -28,9 +27,9 @@ extern "C" {
 #include "tdataformat.h"
 #include "talgo.h"
 
-#define DEFAULT_PAGE_SIZE (1024L*4)  // 16k larger than the SHistoInfo
-#define MAX_TMPFILE_PATH_LENGTH PATH_MAX
+#define MAX_TMPFILE_PATH_LENGTH        PATH_MAX
 #define INITIAL_ALLOCATION_BUFFER_SIZE 64
+#define DEFAULT_PAGE_SIZE              (4096L)  // 16k larger than the SHistoInfo
 
 typedef enum EXT_BUFFER_FLUSH_MODEL {
   /*
@@ -126,7 +125,7 @@ typedef struct tExtMemBuffer {
  * @param pModel
  * @return
  */
-tExtMemBuffer *createExtMemBuffer(int32_t inMemSize, int32_t elemSize, SColumnModel *pModel);
+tExtMemBuffer *createExtMemBuffer(int32_t inMemSize, int32_t elemSize, int32_t pagesize, SColumnModel *pModel);
 
 /**
  *

src/query/inc/qResultbuf.h

@@ -13,50 +13,85 @@
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef TDENGINE_VNODEQUERYUTIL_H
-#define TDENGINE_VNODEQUERYUTIL_H
+#ifndef TDENGINE_QRESULTBUF_H
+#define TDENGINE_QRESULTBUF_H
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
+#include <tlist.h>
 #include "hash.h"
 #include "os.h"
 #include "qExtbuffer.h"
+#include "tlockfree.h"
 
 typedef struct SArray* SIDList;
 
+typedef struct SPageDiskInfo {
+  int32_t offset;
+  int32_t length;
+} SPageDiskInfo;
+
+typedef struct SPageInfo {
+  SListNode*    pn;       // point to list node
+  int32_t       pageId;
+  SPageDiskInfo info;
+  void*         pData;
+  bool          used;     // set current page is in used
+} SPageInfo;
+
+typedef struct SFreeListItem {
+  int32_t offset;
+  int32_t len;
+} SFreeListItem;
+
+typedef struct SResultBufStatis {
+  int32_t flushBytes;
+  int32_t loadBytes;
+  int32_t getPages;
+  int32_t releasePages;
+  int32_t flushPages;
+} SResultBufStatis;
+
 typedef struct SDiskbasedResultBuf {
   int32_t   numOfRowsPerPage;
   int32_t   numOfPages;
   int64_t   totalBufSize;
-  int32_t   fd;                  // data file fd
+  int64_t   fileSize;            // disk file size
+  FILE*     file;
   int32_t   allocateId;          // allocated page id
-  int32_t   incStep;             // minimum allocated pages
-  void*     pBuf;                // mmap buffer pointer
   char*     path;                // file path
   int32_t   pageSize;            // current used page size
   int32_t   inMemPages;          // numOfPages that are allocated in memory
-  SHashObj* idsTable;            // id hash table
-  SIDList   list;                // for each id, there is a page id list
-
-  void*     iBuf;                // inmemory buf
-  void*     handle;              // for debug purpose
+  SHashObj* groupSet;            // id hash table
+  SHashObj* all;
+  SList*    lruList;
   void*     emptyDummyIdList;    // dummy id list
+  void*     assistBuf;           // assistant buffer for compress/decompress data
+  SArray*   pFree;               // free area in file
+  bool      comp;                // compressed before flushed to disk
+  int32_t   nextPos;             // next page flush position
+
+  const void*      handle;        // for debug purpose
+  SResultBufStatis statis;
 } SDiskbasedResultBuf;
 
-#define DEFAULT_INTERN_BUF_PAGE_SIZE (1024L)
+#define DEFAULT_INTERN_BUF_PAGE_SIZE  (4096L)
 #define DEFAULT_INMEM_BUF_PAGES       10
+#define PAGE_INFO_INITIALIZER         (SPageDiskInfo){-1, -1}
 
 /**
  * create disk-based result buffer
  * @param pResultBuf
- * @param size
  * @param rowSize
+ * @param pagesize
+ * @param inMemPages
+ * @param handle
  * @return
  */
-int32_t createDiskbasedResultBuffer(SDiskbasedResultBuf** pResultBuf, int32_t numOfPages, int32_t rowSize, int32_t pagesize,
-    int32_t inMemPages, void* handle);
+int32_t createDiskbasedResultBuffer(SDiskbasedResultBuf** pResultBuf, int32_t rowSize, int32_t pagesize,
+                                    int32_t inMemBufSize, const void* handle);
 
 /**
  *
@@ -72,7 +107,7 @@ tFilePage* getNewDataBuf(SDiskbasedResultBuf* pResultBuf, int32_t groupId, int32
  * @param pResultBuf
  * @return
  */
-int32_t getNumOfRowsPerPage(SDiskbasedResultBuf* pResultBuf);
+size_t getNumOfRowsPerPage(const SDiskbasedResultBuf* pResultBuf);
 
 /**
  *
@@ -88,42 +123,52 @@ SIDList getDataBufPagesIdList(SDiskbasedResultBuf* pResultBuf, int32_t groupId);
  * @param id
  * @return
  */
-static FORCE_INLINE tFilePage* getResBufPage(SDiskbasedResultBuf* pResultBuf, int32_t id) {
-  if (id < pResultBuf->inMemPages) {
-    return (tFilePage*) ((char*) pResultBuf->iBuf + id * pResultBuf->pageSize);
-  } else {
-    return (tFilePage*) ((char*) pResultBuf->pBuf + (id - pResultBuf->inMemPages) * pResultBuf->pageSize);
-  }
-}
+tFilePage* getResBufPage(SDiskbasedResultBuf* pResultBuf, int32_t id);
+
+/**
+ * release the referenced buf pages
+ * @param pResultBuf
+ * @param page
+ */
+void releaseResBufPage(SDiskbasedResultBuf* pResultBuf, void* page);
+
+/**
+ *
+ * @param pResultBuf
+ * @param pi
+ */
+void releaseResBufPageInfo(SDiskbasedResultBuf* pResultBuf, SPageInfo* pi);
+
+
 /**
  * get the total buffer size in the format of disk file
  * @param pResultBuf
  * @return
  */
-int32_t getResBufSize(SDiskbasedResultBuf* pResultBuf);
+size_t getResBufSize(const SDiskbasedResultBuf* pResultBuf);
 
 /**
  * get the number of groups in the result buffer
  * @param pResultBuf
  * @return
  */
-int32_t getNumOfResultBufGroupId(SDiskbasedResultBuf* pResultBuf);
+size_t getNumOfResultBufGroupId(const SDiskbasedResultBuf* pResultBuf);
 
 /**
  * destroy result buffer
  * @param pResultBuf
  */
-void destroyResultBuf(SDiskbasedResultBuf* pResultBuf, void* handle);
+void destroyResultBuf(SDiskbasedResultBuf* pResultBuf);
 
 /**
  *
  * @param pList
  * @return
  */
-int32_t getLastPageId(SIDList pList);
+SPageInfo* getLastPageInfo(SIDList pList);
 
 #ifdef __cplusplus
 }
 #endif
 
-#endif  // TDENGINE_VNODEQUERYUTIL_H
+#endif  // TDENGINE_QRESULTBUF_H

src/query/inc/qUtil.h

@@ -45,13 +45,14 @@ bool isWindowResClosed(SWindowResInfo *pWindowResInfo, int32_t slot);
 
 int32_t createQueryResultInfo(SQuery *pQuery, SWindowResult *pResultRow, bool isSTableQuery, size_t interBufSize);
 
-static FORCE_INLINE char *getPosInResultPage(SQueryRuntimeEnv *pRuntimeEnv, int32_t columnIndex, SWindowResult *pResult) {
+static FORCE_INLINE char *getPosInResultPage(SQueryRuntimeEnv *pRuntimeEnv, int32_t columnIndex, SWindowResult *pResult,
+    tFilePage* page) {
   assert(pResult != NULL && pRuntimeEnv != NULL);
 
   SQuery    *pQuery = pRuntimeEnv->pQuery;
-  tFilePage *page = getResBufPage(pRuntimeEnv->pResultBuf, pResult->pos.pageId);
-  int32_t realRowId = pResult->pos.rowId * GET_ROW_PARAM_FOR_MULTIOUTPUT(pQuery, pRuntimeEnv->topBotQuery, pRuntimeEnv->stableQuery);
+//  tFilePage *page = getResBufPage(pRuntimeEnv->pResultBuf, pResult->pos.pageId);
 
+  int32_t realRowId = pResult->pos.rowId * GET_ROW_PARAM_FOR_MULTIOUTPUT(pQuery, pRuntimeEnv->topBotQuery, pRuntimeEnv->stableQuery);
   return ((char *)page->data) + pRuntimeEnv->offset[columnIndex] * pRuntimeEnv->numOfRowsPerPage +
       pQuery->pSelectExpr[columnIndex].bytes * realRowId;
 }

src/query/src/qAst.c

@@ -18,8 +18,8 @@
 
 #include "exception.h"
 #include "qAst.h"
+#include "qSqlparser.h"
 #include "qSyntaxtreefunction.h"
-#include "qsqlparser.h"
 #include "taosdef.h"
 #include "taosmsg.h"
 #include "tarray.h"

src/query/src/qExtbuffer.c

@@ -28,10 +28,10 @@
 /*
  * SColumnModel is deeply copy
  */
-tExtMemBuffer* createExtMemBuffer(int32_t inMemSize, int32_t elemSize, SColumnModel *pModel) {
+tExtMemBuffer* createExtMemBuffer(int32_t inMemSize, int32_t elemSize, int32_t pagesize, SColumnModel *pModel) {
   tExtMemBuffer* pMemBuffer = (tExtMemBuffer *)calloc(1, sizeof(tExtMemBuffer));
 
-  pMemBuffer->pageSize = DEFAULT_PAGE_SIZE;
+  pMemBuffer->pageSize = pagesize;
   pMemBuffer->inMemCapacity = ALIGN8(inMemSize) / pMemBuffer->pageSize;
   pMemBuffer->nElemSize = elemSize;
 

src/query/src/qParserImpl.c

@@ -14,7 +14,7 @@
  */
 
 #include "os.h"
-#include "qsqlparser.h"
+#include "qSqlparser.h"
 #include "queryLog.h"
 #include "taosdef.h"
 #include "taosmsg.h"

src/query/src/qPercentile.c

@@ -535,7 +535,7 @@ void tMemBucketPut(tMemBucket *pBucket, void *data, int32_t numOfRows) {
 
     if (pSeg->pBuffer[slotIdx] == NULL) {
       pSeg->pBuffer[slotIdx] = createExtMemBuffer(pBucket->numOfTotalPages * pBucket->pageSize, pBucket->nElemSize,
-                                                  pBucket->pOrderDesc->pColumnModel);
+                                                  pBucket->pageSize, pBucket->pOrderDesc->pColumnModel);
       pSeg->pBuffer[slotIdx]->flushModel = SINGLE_APPEND_MODEL;
       pBucket->pOrderDesc->pColumnModel->capacity = pSeg->pBuffer[slotIdx]->numOfElemsPerPage;
     }

src/query/src/qResultbuf.c

 #include "qResultbuf.h"
+#include "stddef.h"
+#include "tscompression.h"
 #include "hash.h"
 #include "qExtbuffer.h"
 #include "queryLog.h"
 #include "taoserror.h"
 
-int32_t createDiskbasedResultBuffer(SDiskbasedResultBuf** pResultBuf, int32_t numOfPages, int32_t rowSize,
-    int32_t pagesize, int32_t inMemPages, void* handle) {
+#define GET_DATA_PAYLOAD(_p) ((_p)->pData + POINTER_BYTES)
 
+int32_t createDiskbasedResultBuffer(SDiskbasedResultBuf** pResultBuf, int32_t rowSize, int32_t pagesize,
+                                    int32_t inMemBufSize, const void* handle) {
   *pResultBuf = calloc(1, sizeof(SDiskbasedResultBuf));
+
   SDiskbasedResultBuf* pResBuf = *pResultBuf;
   if (pResBuf == NULL) {
     return TSDB_CODE_COM_OUT_OF_MEMORY;  
   }
 
-  pResBuf->pageSize   = pagesize;
-  pResBuf->numOfPages = inMemPages;  // all pages are in buffer in the first place
-  pResBuf->inMemPages = inMemPages;
-  assert(inMemPages <= numOfPages);
-
-  pResBuf->numOfRowsPerPage = (pagesize - sizeof(tFilePage)) / rowSize;
+  pResBuf->pageSize     = pagesize;
+  pResBuf->numOfPages   = 0;                        // all pages are in buffer in the first place
+  pResBuf->totalBufSize = 0;
+  pResBuf->inMemPages   = inMemBufSize/pagesize;    // maximum allowed pages, it is a soft limit.
+  pResBuf->allocateId   = -1;
+  pResBuf->comp         = true;
+  pResBuf->file         = NULL;
+  pResBuf->handle       = handle;
+  pResBuf->fileSize = 0;
 
-  pResBuf->totalBufSize = pResBuf->numOfPages * pagesize;
-  pResBuf->incStep = 4;
-  pResBuf->allocateId = -1;
+  // at least more than 2 pages must be in memory
+  assert(inMemBufSize >= pagesize * 2);
 
-  pResBuf->iBuf = calloc(pResBuf->inMemPages, pResBuf->pageSize);
+  pResBuf->numOfRowsPerPage = (pagesize - sizeof(tFilePage)) / rowSize;
+  pResBuf->lruList = tdListNew(POINTER_BYTES);
 
   // init id hash table
-  pResBuf->idsTable = taosHashInit(numOfPages, taosGetDefaultHashFunction(TSDB_DATA_TYPE_INT), false);
-  pResBuf->list = taosArrayInit(numOfPages, POINTER_BYTES);
+  pResBuf->groupSet  = taosHashInit(10, taosGetDefaultHashFunction(TSDB_DATA_TYPE_INT), false);
+  pResBuf->assistBuf = malloc(pResBuf->pageSize + 2); // EXTRA BYTES
+  pResBuf->all = taosHashInit(10, taosGetDefaultHashFunction(TSDB_DATA_TYPE_INT), false);
 
   char path[PATH_MAX] = {0};
-  getTmpfilePath("tsdb_qbuf", path);
+  getTmpfilePath("qbuf", path);
   pResBuf->path = strdup(path);
 
-  pResBuf->fd = FD_INITIALIZER;
-  pResBuf->pBuf = NULL;
   pResBuf->emptyDummyIdList = taosArrayInit(1, sizeof(int32_t));
 
-  qDebug("QInfo:%p create resBuf for output, page size:%d, initial pages:%d, %" PRId64 "bytes", handle,
-      pResBuf->pageSize, pResBuf->numOfPages, pResBuf->totalBufSize);
-  
+  qDebug("QInfo:%p create resBuf for output, page size:%d, inmem buf pages:%d, file:%s", handle, pResBuf->pageSize,
+         pResBuf->inMemPages, pResBuf->path);
+
   return TSDB_CODE_SUCCESS;
 }
 
-int32_t getNumOfResultBufGroupId(SDiskbasedResultBuf* pResultBuf) { return taosHashGetSize(pResultBuf->idsTable); }
-
-int32_t getResBufSize(SDiskbasedResultBuf* pResultBuf) { return pResultBuf->totalBufSize; }
-
-#define NUM_OF_PAGES_ON_DISK(_r) ((_r)->numOfPages - (_r)->inMemPages)
-#define FILE_SIZE_ON_DISK(_r) (NUM_OF_PAGES_ON_DISK(_r) * (_r)->pageSize)
-
-static int32_t createDiskResidesBuf(SDiskbasedResultBuf* pResultBuf) {
-  pResultBuf->fd = open(pResultBuf->path, O_CREAT | O_RDWR | O_TRUNC, 0666);
-  if (!FD_VALID(pResultBuf->fd)) {
+static int32_t createDiskFile(SDiskbasedResultBuf* pResultBuf) {
+  pResultBuf->file = fopen(pResultBuf->path, "wb+");
+  if (pResultBuf->file == NULL) {
     qError("failed to create tmp file: %s on disk. %s", pResultBuf->path, strerror(errno));
     return TAOS_SYSTEM_ERROR(errno);
   }
 
-  assert(pResultBuf->numOfPages == pResultBuf->inMemPages);
-  pResultBuf->numOfPages += pResultBuf->incStep;
+  return TSDB_CODE_SUCCESS;
+}
 
-  int32_t ret = ftruncate(pResultBuf->fd, NUM_OF_PAGES_ON_DISK(pResultBuf) * pResultBuf->pageSize);
-  if (ret != TSDB_CODE_SUCCESS) {
-    qError("failed to create tmp file: %s on disk. %s", pResultBuf->path, strerror(errno));
-    return TAOS_SYSTEM_ERROR(errno);
+static char* doCompressData(void* data, int32_t srcSize, int32_t *dst, SDiskbasedResultBuf* pResultBuf) { // do nothing
+  if (!pResultBuf->comp) {
+    *dst = srcSize;
+    return data;
   }
 
-  pResultBuf->pBuf = mmap(NULL, FILE_SIZE_ON_DISK(pResultBuf), PROT_READ | PROT_WRITE, MAP_SHARED, pResultBuf->fd, 0);
-  if (pResultBuf->pBuf == MAP_FAILED) {
-    qError("QInfo:%p failed to map temp file: %s. %s", pResultBuf->handle, pResultBuf->path, strerror(errno));
-    return TAOS_SYSTEM_ERROR(errno);
+  *dst = tsCompressString(data, srcSize, 1, pResultBuf->assistBuf, srcSize, ONE_STAGE_COMP, NULL, 0);
+
+  memcpy(data, pResultBuf->assistBuf, *dst);
+  return data;
+}
+
+static char* doDecompressData(void* data, int32_t srcSize, int32_t *dst, SDiskbasedResultBuf* pResultBuf) { // do nothing
+  if (!pResultBuf->comp) {
+    *dst = srcSize;
+    return data;
   }
 
-  pResultBuf->totalBufSize = pResultBuf->numOfPages * pResultBuf->pageSize;
-  return TSDB_CODE_SUCCESS;
+  *dst = tsDecompressString(data, srcSize, 1, pResultBuf->assistBuf, pResultBuf->pageSize, ONE_STAGE_COMP, NULL, 0);
+
+  memcpy(data, pResultBuf->assistBuf, *dst);
+  return data;
 }
 
-static int32_t extendDiskFileSize(SDiskbasedResultBuf* pResultBuf, int32_t incNumOfPages) {
-  assert(pResultBuf->numOfPages * pResultBuf->pageSize == pResultBuf->totalBufSize);
-  int32_t ret = TSDB_CODE_SUCCESS;
+static int32_t allocatePositionInFile(SDiskbasedResultBuf* pResultBuf, size_t size) {
+  if (pResultBuf->pFree == NULL) {
+    return pResultBuf->nextPos;
+  } else {
+    int32_t offset = -1;
+
+    size_t num = taosArrayGetSize(pResultBuf->pFree);
+    for(int32_t i = 0; i < num; ++i) {
+      SFreeListItem* pi = taosArrayGet(pResultBuf->pFree, i);
+      if (pi->len >= size) {
+        offset = pi->offset;
+        pi->offset += size;
+        pi->len -= size;
+
+        return offset;
+      }
+    }
+
+    // no available recycle space, allocate new area in file
+    return pResultBuf->nextPos;
+  }
+}
+
+static char* doFlushPageToDisk(SDiskbasedResultBuf* pResultBuf, SPageInfo* pg) {
+  assert(!pg->used && pg->pData != NULL);
+
+  int32_t size = -1;
+  char* t = doCompressData(GET_DATA_PAYLOAD(pg), pResultBuf->pageSize, &size, pResultBuf);
+
+  // this page is flushed to disk for the first time
+  if (pg->info.offset == -1) {
+    pg->info.offset = allocatePositionInFile(pResultBuf, size);
+    pResultBuf->nextPos += size;
 
-  if (pResultBuf->pBuf == NULL) {
-    assert(pResultBuf->fd == FD_INITIALIZER);
+    fseek(pResultBuf->file, pg->info.offset, SEEK_SET);
+    /*int32_t ret =*/ fwrite(t, 1, size, pResultBuf->file);
 
-    if ((ret = createDiskResidesBuf(pResultBuf)) != TSDB_CODE_SUCCESS) {
-      return ret;
+    if (pResultBuf->fileSize < pg->info.offset + pg->info.length) {
+      pResultBuf->fileSize = pg->info.offset + pg->info.length;
     }
   } else {
-    ret = munmap(pResultBuf->pBuf, FILE_SIZE_ON_DISK(pResultBuf));
-    pResultBuf->numOfPages += incNumOfPages;
-
-    /*
-     * disk-based output buffer is exhausted, try to extend the disk-based buffer, the available disk space may
-     * be insufficient
-     */
-    ret = ftruncate(pResultBuf->fd, NUM_OF_PAGES_ON_DISK(pResultBuf) * pResultBuf->pageSize);
-    if (ret != TSDB_CODE_SUCCESS) {
-      //    dError("QInfo:%p failed to create intermediate result output file:%s. %s", pQInfo, pSupporter->extBufFile,
-      //           strerror(errno));
-      return TSDB_CODE_QRY_NO_DISKSPACE;
+    // length becomes greater, current space is not enough, allocate new place, otherwise, do nothing
+    if (pg->info.length < size) {
+      // 1. add current space to free list
+      taosArrayPush(pResultBuf->pFree, &pg->info);
+
+      // 2. allocate new position, and update the info
+      pg->info.offset = allocatePositionInFile(pResultBuf, size);
+      pResultBuf->nextPos += size;
     }
 
-    pResultBuf->totalBufSize = pResultBuf->numOfPages * pResultBuf->pageSize;
-    pResultBuf->pBuf = mmap(NULL, FILE_SIZE_ON_DISK(pResultBuf), PROT_READ | PROT_WRITE, MAP_SHARED, pResultBuf->fd, 0);
+    //3. write to disk.
+    fseek(pResultBuf->file, pg->info.offset, SEEK_SET);
+    fwrite(t, size, 1, pResultBuf->file);
 
-    if (pResultBuf->pBuf == MAP_FAILED) {
-      //    dError("QInfo:%p failed to map temp file: %s. %s", pQInfo, pSupporter->extBufFile, strerror(errno));
-      return TSDB_CODE_QRY_OUT_OF_MEMORY;
+    if (pResultBuf->fileSize < pg->info.offset + pg->info.length) {
+      pResultBuf->fileSize = pg->info.offset + pg->info.length;
     }
   }
 
-  return TSDB_CODE_SUCCESS;
+  char* ret = pg->pData;
+  memset(ret, 0, pResultBuf->pageSize);
+
+  pg->pData = NULL;
+  pg->info.length = size;
+
+  pResultBuf->statis.flushBytes += pg->info.length;
+
+  return ret;
 }
 
-#define NO_AVAILABLE_PAGES(_b) ((_b)->allocateId == (_b)->numOfPages - 1)
+static char* flushPageToDisk(SDiskbasedResultBuf* pResultBuf, SPageInfo* pg) {
+  int32_t ret = TSDB_CODE_SUCCESS;
+  assert(pResultBuf->numOfPages * pResultBuf->pageSize == pResultBuf->totalBufSize && pResultBuf->numOfPages >= pResultBuf->inMemPages);
 
-static FORCE_INLINE int32_t getGroupIndex(SDiskbasedResultBuf* pResultBuf, int32_t groupId) {
-  assert(pResultBuf != NULL);
+  if (pResultBuf->file == NULL) {
+    if ((ret = createDiskFile(pResultBuf)) != TSDB_CODE_SUCCESS) {
+      terrno = ret;
+      return NULL;
+    }
+  }
+
+  return doFlushPageToDisk(pResultBuf, pg);
+}
+
+// load file block data in disk
+static char* loadPageFromDisk(SDiskbasedResultBuf* pResultBuf, SPageInfo* pg) {
+  int32_t ret = fseek(pResultBuf->file, pg->info.offset, SEEK_SET);
+  ret = fread(GET_DATA_PAYLOAD(pg), 1, pg->info.length, pResultBuf->file);
+  if (ret != pg->info.length) {
+    terrno = errno;
+    return NULL;
+  }
+
+  pResultBuf->statis.loadBytes += pg->info.length;
 
-  char* p = taosHashGet(pResultBuf->idsTable, (const char*)&groupId, sizeof(int32_t));
+  int32_t fullSize = 0;
+  doDecompressData(GET_DATA_PAYLOAD(pg), pg->info.length, &fullSize, pResultBuf);
+
+  return GET_DATA_PAYLOAD(pg);
+}
+
+#define NO_AVAILABLE_PAGES(_b) ((_b)->numOfPages >= (_b)->inMemPages)
+
+static SIDList addNewGroup(SDiskbasedResultBuf* pResultBuf, int32_t groupId) {
+  assert(taosHashGet(pResultBuf->groupSet, (const char*) &groupId, sizeof(int32_t)) == NULL);
+
+  SArray* pa = taosArrayInit(1, POINTER_BYTES);
+  int32_t ret = taosHashPut(pResultBuf->groupSet, (const char*)&groupId, sizeof(int32_t), &pa, POINTER_BYTES);
+  assert(ret == 0);
+
+  return pa;
+}
+
+static SPageInfo* registerPage(SDiskbasedResultBuf* pResultBuf, int32_t groupId, int32_t pageId) {
+  SIDList list = NULL;
+
+  char** p = taosHashGet(pResultBuf->groupSet, (const char*)&groupId, sizeof(int32_t));
   if (p == NULL) {  // it is a new group id
-    return -1;
+    list = addNewGroup(pResultBuf, groupId);
+  } else {
+    list = (SIDList) (*p);
   }
 
-  int32_t slot = GET_INT32_VAL(p);
-  assert(slot >= 0 && slot < taosHashGetSize(pResultBuf->idsTable));
+  pResultBuf->numOfPages += 1;
 
-  return slot;
+  SPageInfo* ppi = malloc(sizeof(SPageInfo));//{ .info = PAGE_INFO_INITIALIZER, .pageId = pageId, .pn = NULL};
+  ppi->info     = PAGE_INFO_INITIALIZER;
+  ppi->pageId   = pageId;
+  ppi->pData    = NULL;
+  ppi->pn       = NULL;
+  ppi->used     = true;
+
+  return *(SPageInfo**) taosArrayPush(list, &ppi);
 }
 
-static int32_t addNewGroupId(SDiskbasedResultBuf* pResultBuf, int32_t groupId) {
-  int32_t num = getNumOfResultBufGroupId(pResultBuf); // the num is the newest allocated group id slot
-  taosHashPut(pResultBuf->idsTable, (const char*)&groupId, sizeof(int32_t), &num, sizeof(int32_t));
+static SListNode* getEldestUnrefedPage(SDiskbasedResultBuf* pResultBuf) {
+  SListIter iter = {0};
+  tdListInitIter(pResultBuf->lruList, &iter, TD_LIST_BACKWARD);
+
+  SListNode* pn = NULL;
+  while((pn = tdListNext(&iter)) != NULL) {
+    assert(pn != NULL);
+
+    SPageInfo* pageInfo = *(SPageInfo**) pn->data;
+    assert(pageInfo->pageId >= 0 && pageInfo->pn == pn);
 
-  SArray* pa = taosArrayInit(1, sizeof(int32_t));
-  taosArrayPush(pResultBuf->list, &pa);
+    if (!pageInfo->used) {
+      break;
+    }
+  }
 
-  assert(taosArrayGetSize(pResultBuf->list) == taosHashGetSize(pResultBuf->idsTable));
-  return num;
+  return pn;
 }
 
-static void registerPageId(SDiskbasedResultBuf* pResultBuf, int32_t groupId, int32_t pageId) {
-  int32_t slot = getGroupIndex(pResultBuf, groupId);
-  if (slot < 0) {
-    slot = addNewGroupId(pResultBuf, groupId);
+static char* evicOneDataPage(SDiskbasedResultBuf* pResultBuf) {
+  char* bufPage = NULL;
+  SListNode* pn = getEldestUnrefedPage(pResultBuf);
+
+  // all pages are referenced by user, try to allocate new space
+  if (pn == NULL) {
+    int32_t prev = pResultBuf->inMemPages;
+    pResultBuf->inMemPages = pResultBuf->inMemPages * 1.5;
+
+    qWarn("%p in memory buf page not sufficient, expand from %d to %d, page size:%d", pResultBuf, prev,
+          pResultBuf->inMemPages, pResultBuf->pageSize);
+  } else {
+    pResultBuf->statis.flushPages += 1;
+    tdListPopNode(pResultBuf->lruList, pn);
+
+    SPageInfo* d = *(SPageInfo**) pn->data;
+    assert(d->pn == pn);
+
+    d->pn = NULL;
+    tfree(pn);
+
+    bufPage = flushPageToDisk(pResultBuf, d);
   }
 
-  SIDList pList = taosArrayGetP(pResultBuf->list, slot);
-  taosArrayPush(pList, &pageId);
+  return bufPage;
+}
+
+static void lruListPushFront(SList *pList, SPageInfo* pi) {
+  tdListPrepend(pList, &pi);
+  SListNode* front = tdListGetHead(pList);
+  pi->pn = front;
+}
+
+static void lruListMoveToFront(SList *pList, SPageInfo* pi) {
+  tdListPopNode(pList, pi->pn);
+  tdListPrependNode(pList, pi->pn);
 }
 
 tFilePage* getNewDataBuf(SDiskbasedResultBuf* pResultBuf, int32_t groupId, int32_t* pageId) {
+  pResultBuf->statis.getPages += 1;
+
+  char* availablePage = NULL;
   if (NO_AVAILABLE_PAGES(pResultBuf)) {
-    if (extendDiskFileSize(pResultBuf, pResultBuf->incStep) != TSDB_CODE_SUCCESS) {
-      return NULL;
-    }
+    availablePage = evicOneDataPage(pResultBuf);
   }
 
   // register new id in this group
   *pageId = (++pResultBuf->allocateId);
-  registerPageId(pResultBuf, groupId, *pageId);
 
-  // clear memory for the new page
-  tFilePage* page = getResBufPage(pResultBuf, *pageId);
-  memset(page, 0, pResultBuf->pageSize);
-  
-  return page;
+  // register page id info
+  SPageInfo* pi = registerPage(pResultBuf, groupId, *pageId);
+
+  // add to LRU list
+  assert(listNEles(pResultBuf->lruList) < pResultBuf->inMemPages && pResultBuf->inMemPages > 0);
+
+  lruListPushFront(pResultBuf->lruList, pi);
+
+  // add to hash map
+  taosHashPut(pResultBuf->all, pageId, sizeof(int32_t), &pi, POINTER_BYTES);
+
+  // allocate buf
+  if (availablePage == NULL) {
+    pi->pData = calloc(1, pResultBuf->pageSize + POINTER_BYTES);
+  } else {
+    pi->pData = availablePage;
+  }
+
+  pResultBuf->totalBufSize += pResultBuf->pageSize;
+
+  ((void**)pi->pData)[0] = pi;
+  pi->used = true;
+
+  return GET_DATA_PAYLOAD(pi);
+}
+
+tFilePage* getResBufPage(SDiskbasedResultBuf* pResultBuf, int32_t id) {
+  assert(pResultBuf != NULL && id >= 0);
+  pResultBuf->statis.getPages += 1;
+
+  SPageInfo** pi = taosHashGet(pResultBuf->all, &id, sizeof(int32_t));
+  assert(pi != NULL && *pi != NULL);
+
+  if ((*pi)->pData != NULL) { // it is in memory
+    // no need to update the LRU list if only one page exists
+    if (pResultBuf->numOfPages == 1) {
+      (*pi)->used = true;
+      return GET_DATA_PAYLOAD(*pi);
+    }
+
+    SPageInfo** pInfo = (SPageInfo**) ((*pi)->pn->data);
+    assert(*pInfo == *pi);
+
+    lruListMoveToFront(pResultBuf->lruList, (*pi));
+    (*pi)->used = true;
+
+    return GET_DATA_PAYLOAD(*pi);
+
+  } else { // not in memory
+    assert((*pi)->pData == NULL && (*pi)->pn == NULL && (*pi)->info.length >= 0 && (*pi)->info.offset >= 0);
+
+    char* availablePage = NULL;
+    if (NO_AVAILABLE_PAGES(pResultBuf)) {
+      availablePage = evicOneDataPage(pResultBuf);
+    }
+
+    if (availablePage == NULL) {
+      (*pi)->pData = calloc(1, pResultBuf->pageSize + POINTER_BYTES);
+    } else {
+      (*pi)->pData = availablePage;
+    }
+
+    ((void**)((*pi)->pData))[0] = (*pi);
+
+    lruListPushFront(pResultBuf->lruList, *pi);
+    loadPageFromDisk(pResultBuf, *pi);
+    return GET_DATA_PAYLOAD(*pi);
+  }
 }
 
-int32_t getNumOfRowsPerPage(SDiskbasedResultBuf* pResultBuf) { return pResultBuf->numOfRowsPerPage; }
+void releaseResBufPage(SDiskbasedResultBuf* pResultBuf, void* page) {
+  assert(pResultBuf != NULL && page != NULL);
+  char* p = (char*) page - POINTER_BYTES;
+
+  SPageInfo* ppi = ((SPageInfo**) p)[0];
+  releaseResBufPageInfo(pResultBuf, ppi);
+}
+
+void releaseResBufPageInfo(SDiskbasedResultBuf* pResultBuf, SPageInfo* pi) {
+  assert(pi->pData != NULL && pi->used);
+
+  pi->used = false;
+  pResultBuf->statis.releasePages += 1;
+}
+
+size_t getNumOfRowsPerPage(const SDiskbasedResultBuf* pResultBuf) { return pResultBuf->numOfRowsPerPage; }
+
+size_t getNumOfResultBufGroupId(const SDiskbasedResultBuf* pResultBuf) { return taosHashGetSize(pResultBuf->groupSet); }
+
+size_t getResBufSize(const SDiskbasedResultBuf* pResultBuf) { return pResultBuf->totalBufSize; }
 
 SIDList getDataBufPagesIdList(SDiskbasedResultBuf* pResultBuf, int32_t groupId) {
-  int32_t slot = getGroupIndex(pResultBuf, groupId);
-  if (slot < 0) {
+  assert(pResultBuf != NULL);
+
+  char** p = taosHashGet(pResultBuf->groupSet, (const char*)&groupId, sizeof(int32_t));
+  if (p == NULL) {  // it is a new group id
     return pResultBuf->emptyDummyIdList;
   } else {
-    return taosArrayGetP(pResultBuf->list, slot);
+    return (SArray*) (*p);
   }
 }
 
-void destroyResultBuf(SDiskbasedResultBuf* pResultBuf, void* handle) {
+void destroyResultBuf(SDiskbasedResultBuf* pResultBuf) {
   if (pResultBuf == NULL) {
     return;
   }
 
-  if (FD_VALID(pResultBuf->fd)) {
-    qDebug("QInfo:%p disk-based output buffer closed, total:%" PRId64 " bytes, file created:%s, file size:%d", handle,
-        pResultBuf->totalBufSize, pResultBuf->path, FILE_SIZE_ON_DISK(pResultBuf));
+  if (pResultBuf->file != NULL) {
+    qDebug("QInfo:%p disk-based output buffer closed, total:%" PRId64 " bytes, file size:%"PRId64" bytes",
+        pResultBuf->handle, pResultBuf->totalBufSize, pResultBuf->fileSize);
 
-    close(pResultBuf->fd);
-    munmap(pResultBuf->pBuf, FILE_SIZE_ON_DISK(pResultBuf));
-    pResultBuf->pBuf = NULL;
+    fclose(pResultBuf->file);
   } else {
-    qDebug("QInfo:%p disk-based output buffer closed, total:%" PRId64 " bytes, no file created", handle,
+    qDebug("QInfo:%p disk-based output buffer closed, total:%" PRId64 " bytes, no file created", pResultBuf->handle,
            pResultBuf->totalBufSize);
   }
 
   unlink(pResultBuf->path);
   tfree(pResultBuf->path);
 
-  size_t size = taosArrayGetSize(pResultBuf->list);
-  for (int32_t i = 0; i < size; ++i) {
-    SArray* pa = taosArrayGetP(pResultBuf->list, i);
-    taosArrayDestroy(pa);
+  SHashMutableIterator* iter = taosHashCreateIter(pResultBuf->groupSet);
+  while(taosHashIterNext(iter)) {
+    SArray** p = (SArray**) taosHashIterGet(iter);
+    size_t n = taosArrayGetSize(*p);
+    for(int32_t i = 0; i < n; ++i) {
+      SPageInfo* pi = taosArrayGetP(*p, i);
+      tfree(pi->pData);
+      tfree(pi);
+    }
+
+    taosArrayDestroy(*p);
   }
 
-  taosArrayDestroy(pResultBuf->list);
+  taosHashDestroyIter(iter);
+
+  tdListFree(pResultBuf->lruList);
   taosArrayDestroy(pResultBuf->emptyDummyIdList);
-  taosHashCleanup(pResultBuf->idsTable);
+  taosHashCleanup(pResultBuf->groupSet);
+  taosHashCleanup(pResultBuf->all);
 
-  tfree(pResultBuf->iBuf);
+  tfree(pResultBuf->assistBuf);
   tfree(pResultBuf);
 }
 
-int32_t getLastPageId(SIDList pList) {
+SPageInfo* getLastPageInfo(SIDList pList) {
   size_t size = taosArrayGetSize(pList);
-  return *(int32_t*) taosArrayGet(pList, size - 1);
+  return (SPageInfo*) taosArrayGetP(pList, size - 1);
 }
 

src/query/src/qUtil.c

@@ -236,11 +236,13 @@ void clearTimeWindowResBuf(SQueryRuntimeEnv *pRuntimeEnv, SWindowResult *pWindow
   if (pWindowRes == NULL) {
     return;
   }
-  
+
+  tFilePage *page = getResBufPage(pRuntimeEnv->pResultBuf, pWindowRes->pos.pageId);
+
   for (int32_t i = 0; i < pRuntimeEnv->pQuery->numOfOutput; ++i) {
     SResultInfo *pResultInfo = &pWindowRes->resultInfo[i];
     
-    char * s = getPosInResultPage(pRuntimeEnv, i, pWindowRes);
+    char * s = getPosInResultPage(pRuntimeEnv, i, pWindowRes, page);
     size_t size = pRuntimeEnv->pQuery->pSelectExpr[i].bytes;
     memset(s, 0, size);
     
@@ -277,8 +279,11 @@ void copyTimeWindowResBuf(SQueryRuntimeEnv *pRuntimeEnv, SWindowResult *dst, con
     memcpy(pDst->interResultBuf, pSrc->interResultBuf, pDst->bufLen);
     
     // copy the output buffer data from src to dst, the position info keep unchanged
-    char * dstBuf = getPosInResultPage(pRuntimeEnv, i, dst);
-    char * srcBuf = getPosInResultPage(pRuntimeEnv, i, (SWindowResult *)src);
+    tFilePage *dstpage = getResBufPage(pRuntimeEnv->pResultBuf, dst->pos.pageId);
+    char * dstBuf = getPosInResultPage(pRuntimeEnv, i, dst, dstpage);
+
+    tFilePage *srcpage = getResBufPage(pRuntimeEnv->pResultBuf, src->pos.pageId);
+    char * srcBuf = getPosInResultPage(pRuntimeEnv, i, (SWindowResult *)src, srcpage);
     size_t s = pRuntimeEnv->pQuery->pSelectExpr[i].bytes;
     
     memcpy(dstBuf, srcBuf, s);

src/query/src/sql.c

@@ -30,7 +30,7 @@
 #include <string.h>
 #include <assert.h>
 #include <stdbool.h>
-#include "qsqlparser.h"
+#include "qSqlparser.h"
 #include "tcmdtype.h"
 #include "tstoken.h"
 #include "ttokendef.h"

src/query/tests/resultBufferTest.cpp

@@ -18,17 +18,144 @@ void simpleTest() {
   tFilePage* pBufPage = getNewDataBuf(pResultBuf, groupId, &pageId);
   ASSERT_TRUE(pBufPage != NULL);
   
-  ASSERT_EQ(getNumOfRowsPerPage(pResultBuf), (16384L - sizeof(int64_t))/64);
-  ASSERT_EQ(getResBufSize(pResultBuf), 1000*16384L);
+  ASSERT_EQ(getResBufSize(pResultBuf), 1024);
   
   SIDList list = getDataBufPagesIdList(pResultBuf, groupId);
   ASSERT_EQ(taosArrayGetSize(list), 1);
   ASSERT_EQ(getNumOfResultBufGroupId(pResultBuf), 1);
-  
-  destroyResultBuf(pResultBuf, NULL);
+
+  releaseResBufPage(pResultBuf, pBufPage);
+
+  tFilePage* pBufPage1 = getNewDataBuf(pResultBuf, groupId, &pageId);
+
+  tFilePage* t = getResBufPage(pResultBuf, pageId);
+  ASSERT_TRUE(t == pBufPage1);
+
+  tFilePage* pBufPage2 = getNewDataBuf(pResultBuf, groupId, &pageId);
+  tFilePage* t1 = getResBufPage(pResultBuf, pageId);
+  ASSERT_TRUE(t1 == pBufPage2);
+
+  tFilePage* pBufPage3 = getNewDataBuf(pResultBuf, groupId, &pageId);
+  tFilePage* t2 = getResBufPage(pResultBuf, pageId);
+  ASSERT_TRUE(t2 == pBufPage3);
+
+  tFilePage* pBufPage4 = getNewDataBuf(pResultBuf, groupId, &pageId);
+  tFilePage* t3 = getResBufPage(pResultBuf, pageId);
+  ASSERT_TRUE(t3 == pBufPage4);
+
+  tFilePage* pBufPage5 = getNewDataBuf(pResultBuf, groupId, &pageId);
+  tFilePage* t4 = getResBufPage(pResultBuf, pageId);
+  ASSERT_TRUE(t4 == pBufPage5);
+
+  destroyResultBuf(pResultBuf);
+}
+
+void writeDownTest() {
+  SDiskbasedResultBuf* pResultBuf = NULL;
+  int32_t ret = createDiskbasedResultBuffer(&pResultBuf, 1000, 64, 1024, 4, NULL);
+
+  int32_t pageId = 0;
+  int32_t writePageId = 0;
+  int32_t groupId = 0;
+  int32_t nx = 12345;
+
+  tFilePage* pBufPage = getNewDataBuf(pResultBuf, groupId, &pageId);
+  ASSERT_TRUE(pBufPage != NULL);
+
+  *(int32_t*)(pBufPage->data) = nx;
+  writePageId = pageId;
+  releaseResBufPage(pResultBuf, pBufPage);
+
+  tFilePage* pBufPage1 = getNewDataBuf(pResultBuf, groupId, &pageId);
+  tFilePage* t1 = getResBufPage(pResultBuf, pageId);
+  ASSERT_TRUE(t1 == pBufPage1);
+  ASSERT_TRUE(pageId == 1);
+
+  tFilePage* pBufPage2 = getNewDataBuf(pResultBuf, groupId, &pageId);
+  tFilePage* t2 = getResBufPage(pResultBuf, pageId);
+  ASSERT_TRUE(t2 == pBufPage2);
+  ASSERT_TRUE(pageId == 2);
+
+  tFilePage* pBufPage3 = getNewDataBuf(pResultBuf, groupId, &pageId);
+  tFilePage* t3 = getResBufPage(pResultBuf, pageId);
+  ASSERT_TRUE(t3 == pBufPage3);
+  ASSERT_TRUE(pageId == 3);
+
+  tFilePage* pBufPage4 = getNewDataBuf(pResultBuf, groupId, &pageId);
+  tFilePage* t4 = getResBufPage(pResultBuf, pageId);
+  ASSERT_TRUE(t4 == pBufPage4);
+  ASSERT_TRUE(pageId == 4);
+  releaseResBufPage(pResultBuf, t4);
+
+  // flush the written page to disk, and read it out again
+  tFilePage* pBufPagex = getResBufPage(pResultBuf, writePageId);
+  ASSERT_EQ(*(int32_t*)pBufPagex->data, nx);
+
+  SArray* pa = getDataBufPagesIdList(pResultBuf, groupId);
+  ASSERT_EQ(taosArrayGetSize(pa), 5);
+
+  destroyResultBuf(pResultBuf);
+}
+
+void recyclePageTest() {
+  SDiskbasedResultBuf* pResultBuf = NULL;
+  int32_t ret = createDiskbasedResultBuffer(&pResultBuf, 1000, 64, 1024, 4, NULL);
+
+  int32_t pageId = 0;
+  int32_t writePageId = 0;
+  int32_t groupId = 0;
+  int32_t nx = 12345;
+
+  tFilePage* pBufPage = getNewDataBuf(pResultBuf, groupId, &pageId);
+  ASSERT_TRUE(pBufPage != NULL);
+  releaseResBufPage(pResultBuf, pBufPage);
+
+  tFilePage* pBufPage1 = getNewDataBuf(pResultBuf, groupId, &pageId);
+  tFilePage* t1 = getResBufPage(pResultBuf, pageId);
+  ASSERT_TRUE(t1 == pBufPage1);
+  ASSERT_TRUE(pageId == 1);
+
+  tFilePage* pBufPage2 = getNewDataBuf(pResultBuf, groupId, &pageId);
+  tFilePage* t2 = getResBufPage(pResultBuf, pageId);
+  ASSERT_TRUE(t2 == pBufPage2);
+  ASSERT_TRUE(pageId == 2);
+
+  tFilePage* pBufPage3 = getNewDataBuf(pResultBuf, groupId, &pageId);
+  tFilePage* t3 = getResBufPage(pResultBuf, pageId);
+  ASSERT_TRUE(t3 == pBufPage3);
+  ASSERT_TRUE(pageId == 3);
+
+  tFilePage* pBufPage4 = getNewDataBuf(pResultBuf, groupId, &pageId);
+  tFilePage* t4 = getResBufPage(pResultBuf, pageId);
+  ASSERT_TRUE(t4 == pBufPage4);
+  ASSERT_TRUE(pageId == 4);
+  releaseResBufPage(pResultBuf, t4);
+  releaseResBufPage(pResultBuf, t4);
+
+  tFilePage* pBufPage5 = getNewDataBuf(pResultBuf, groupId, &pageId);
+  tFilePage* t5 = getResBufPage(pResultBuf, pageId);
+  ASSERT_TRUE(t5 == pBufPage5);
+  ASSERT_TRUE(pageId == 5);
+
+  // flush the written page to disk, and read it out again
+  tFilePage* pBufPagex = getResBufPage(pResultBuf, writePageId);
+  *(int32_t*)(pBufPagex->data) = nx;
+  writePageId = pageId;   // update the data
+  releaseResBufPage(pResultBuf, pBufPagex);
+
+  tFilePage* pBufPagex1 = getResBufPage(pResultBuf, 1);
+
+  SArray* pa = getDataBufPagesIdList(pResultBuf, groupId);
+  ASSERT_EQ(taosArrayGetSize(pa), 6);
+
+  destroyResultBuf(pResultBuf);
 }
 } // namespace
 
+
 TEST(testCase, resultBufferTest) {
+  srand(time(NULL));
   simpleTest();
+  writeDownTest();
+  recyclePageTest();
 }

src/util/inc/tcache.h

@@ -68,8 +68,6 @@ typedef struct {
   int64_t         refreshTime;
   STrashElem *    pTrash;
   char*           name;
-//  void *          tmrCtrl;
-//  void *          pTimer;
   SCacheStatis    statistics;
   SHashObj *      pHashTable;
   __cache_free_fn_t freeFp;

src/util/inc/tlist.h

@@ -55,6 +55,8 @@ int        tdListPrepend(SList *list, void *data);
 int        tdListAppend(SList *list, void *data);
 SListNode *tdListPopHead(SList *list);
 SListNode *tdListPopTail(SList *list);
+SListNode *tdListGetHead(SList *list);
+SListNode *tsListGetTail(SList *list);
 SListNode *tdListPopNode(SList *list, SListNode *node);
 void       tdListMove(SList *src, SList *dst);
 void       tdListDiscard(SList *list);

src/util/src/tcache.c

@@ -343,7 +343,7 @@ void* taosCacheUpdateExpireTimeByName(SCacheObj *pCacheObj, void *key, size_t ke
   SCacheDataNode **ptNode = (SCacheDataNode **)taosHashGet(pCacheObj->pHashTable, key, keyLen);
   if (ptNode != NULL) {
      T_REF_INC(*ptNode);
-    (*ptNode)->expireTime = taosGetTimestampMs() + (*ptNode)->lifespan;
+    (*ptNode)->expireTime = expireTime; // taosGetTimestampMs() + (*ptNode)->lifespan;
   }
 
   __cache_unlock(pCacheObj);
@@ -381,7 +381,7 @@ void *taosCacheAcquireByData(SCacheObj *pCacheObj, void *data) {
 }
 
 void *taosCacheTransfer(SCacheObj *pCacheObj, void **data) {
-  if (pCacheObj == NULL || data == NULL) return NULL;
+  if (pCacheObj == NULL || data == NULL || (*data) == NULL) return NULL;
   
   size_t          offset = offsetof(SCacheDataNode, data);
   SCacheDataNode *ptNode = (SCacheDataNode *)((char *)(*data) - offset);
@@ -419,7 +419,7 @@ void taosCacheRelease(SCacheObj *pCacheObj, void **data, bool _remove) {
   // note: extend lifespan before dec ref count
   bool inTrashCan = pNode->inTrashCan;
 
-  if (pCacheObj->extendLifespan && (!inTrashCan)) {
+  if (pCacheObj->extendLifespan && (!inTrashCan) && (!_remove)) {
     atomic_store_64(&pNode->expireTime, pNode->lifespan + taosGetTimestampMs());
     uDebug("cache:%s data:%p extend life time to %"PRId64 "  before release", pCacheObj->name, pNode->data, pNode->expireTime);
   }
@@ -457,8 +457,9 @@ void taosCacheRelease(SCacheObj *pCacheObj, void **data, bool _remove) {
   } else {
     // NOTE: once refcount is decrease, pNode may be freed by other thread immediately.
     int32_t ref = T_REF_DEC(pNode);
-    uDebug("cache:%s, key:%p, %p is released, refcnt:%d, in trashcan:%d", pCacheObj->name, pNode->key, pNode->data, ref,
-        inTrashCan);
+
+    uDebug("cache:%s, key:%p, %p released, refcnt:%d, data in trancan:%d", pCacheObj->name, pNode->key, pNode->data,
+           ref, inTrashCan);
   }
 }
 
@@ -572,6 +573,7 @@ void taosRemoveFromTrashCan(SCacheObj *pCacheObj, STrashElem *pElem) {
   free(pElem);
 }
 
+// TODO add another lock when scanning trashcan
 void taosTrashCanEmpty(SCacheObj *pCacheObj, bool force) {
   __cache_wr_lock(pCacheObj);
 
@@ -643,6 +645,7 @@ static void doCacheRefresh(SCacheObj* pCacheObj, int64_t time, __cache_free_fn_t
   __cache_wr_lock(pCacheObj);
   while (taosHashIterNext(pIter)) {
     SCacheDataNode *pNode = *(SCacheDataNode **)taosHashIterGet(pIter);
+
     if (pNode->expireTime < time && T_REF_VAL_GET(pNode) <= 0) {
       taosCacheReleaseNode(pCacheObj, pNode);
       continue;
@@ -674,6 +677,7 @@ void* taosCacheTimedRefresh(void *handle) {
 
     // check if current cache object will be deleted every 500ms.
     if (pCacheObj->deleting) {
+      uDebug("%s refresh threads quit", pCacheObj->name);
       break;
     }
 

src/util/src/tcompare.c

 #include "taosdef.h"
 #include "tcompare.h"
-#include <tarray.h>
+#include "tarray.h"
 #include "tutil.h"
 
 int32_t compareInt32Val(const void *pLeft, const void *pRight) {

src/util/src/tlist.c

@@ -76,6 +76,7 @@ int tdListPrepend(SList *list, void *data) {
   SListNode *node = (SListNode *)malloc(sizeof(SListNode) + list->eleSize);
   if (node == NULL) return -1;
 
+  node->next = node->prev = NULL;
   memcpy((void *)(node->data), data, list->eleSize);
   tdListPrependNode(list, node);
 
@@ -121,6 +122,22 @@ SListNode *tdListPopTail(SList *list) {
   return node;
 }
 
+SListNode *tdListGetHead(SList *list) {
+  if (list == NULL || list->numOfEles == 0) {
+    return NULL;
+  }
+
+  return list->head;
+}
+
+SListNode *tsListGetTail(SList *list) {
+  if (list == NULL || list->numOfEles == 0) {
+    return NULL;
+  }
+
+  return list->tail;
+}
+
 SListNode *tdListPopNode(SList *list, SListNode *node) {
   if (list->head == node) {
     list->head = node->next;

src/vnode/src/vnodeRead.c

@@ -71,11 +71,45 @@ static void vnodePutItemIntoReadQueue(SVnodeObj *pVnode, void *qhandle) {
   pRead->rpcMsg.msgType = TSDB_MSG_TYPE_QUERY;
   pRead->pCont = qhandle;
   pRead->contLen = 0;
+  pRead->rpcMsg.handle = NULL;
 
   atomic_add_fetch_32(&pVnode->refCount, 1);
   taosWriteQitem(pVnode->rqueue, TAOS_QTYPE_QUERY, pRead);
 }
 
+static int32_t vnodeDumpQueryResult(SRspRet *pRet, void* pVnode, void* handle, bool* freeHandle) {
+  bool continueExec = false;
+
+  int32_t code = TSDB_CODE_SUCCESS;
+  if ((code = qDumpRetrieveResult(handle, (SRetrieveTableRsp **)&pRet->rsp, &pRet->len, &continueExec)) == TSDB_CODE_SUCCESS) {
+    if (continueExec) {
+      vDebug("QInfo:%p add to query task queue for exec", handle);
+      vnodePutItemIntoReadQueue(pVnode, handle);
+      pRet->qhandle = handle;
+      *freeHandle = false;
+    } else {
+      vDebug("QInfo:%p exec completed", handle);
+      *freeHandle = true;
+    }
+  } else {
+    pRet->rsp = (SRetrieveTableRsp *)rpcMallocCont(sizeof(SRetrieveTableRsp));
+    memset(pRet->rsp, 0, sizeof(SRetrieveTableRsp));
+    *freeHandle = true;
+  }
+
+  return code;
+}
+
+static void vnodeBuildNoResultQueryRsp(SRspRet* pRet) {
+  pRet->rsp = (SRetrieveTableRsp *)rpcMallocCont(sizeof(SRetrieveTableRsp));
+  pRet->len = sizeof(SRetrieveTableRsp);
+
+  memset(pRet->rsp, 0, sizeof(SRetrieveTableRsp));
+  SRetrieveTableRsp* pRsp = pRet->rsp;
+
+  pRsp->completed = true;
+}
+
 static int32_t vnodeProcessQueryMsg(SVnodeObj *pVnode, SReadMsg *pReadMsg) {
   void    *pCont = pReadMsg->pCont;
   int32_t  contLen = pReadMsg->contLen;
@@ -98,6 +132,7 @@ static int32_t vnodeProcessQueryMsg(SVnodeObj *pVnode, SReadMsg *pReadMsg) {
       vWarn("QInfo:%p invalid qhandle, no matched query handle, conn:%p", (void*) killQueryMsg->qhandle, pReadMsg->rpcMsg.handle);
     } else {
       assert(*qhandle == (void*) killQueryMsg->qhandle);
+
       qKillQuery(*qhandle);
       qReleaseQInfo(pVnode->qMgmt, (void**) &qhandle, true);
     }
@@ -110,7 +145,7 @@ static int32_t vnodeProcessQueryMsg(SVnodeObj *pVnode, SReadMsg *pReadMsg) {
 
   if (contLen != 0) {
     qinfo_t pQInfo = NULL;
-    code = qCreateQueryInfo(pVnode->tsdb, pVnode->vgId, pQueryTableMsg, pVnode, &pQInfo);
+    code = qCreateQueryInfo(pVnode->tsdb, pVnode->vgId, pQueryTableMsg, &pQInfo);
 
     SQueryTableRsp *pRsp = (SQueryTableRsp *) rpcMallocCont(sizeof(SQueryTableRsp));
     pRsp->code    = code;
@@ -133,7 +168,6 @@ static int32_t vnodeProcessQueryMsg(SVnodeObj *pVnode, SReadMsg *pReadMsg) {
         pRsp->qhandle = htobe64((uint64_t) pQInfo);
       }
 
-      pQInfo = NULL;
       if (handle != NULL && vnodeNotifyCurrentQhandle(pReadMsg->rpcMsg.handle, *handle, pVnode->vgId) != TSDB_CODE_SUCCESS) {
         vError("vgId:%d, QInfo:%p, query discarded since link is broken, %p", pVnode->vgId, *handle, pReadMsg->rpcMsg.handle);
         pRsp->code = TSDB_CODE_RPC_NETWORK_UNAVAIL;
@@ -153,16 +187,34 @@ static int32_t vnodeProcessQueryMsg(SVnodeObj *pVnode, SReadMsg *pReadMsg) {
 
   } else {
     assert(pCont != NULL);
+
     handle = qAcquireQInfo(pVnode->qMgmt, (uint64_t) pCont);
     if (handle == NULL) {
       vWarn("QInfo:%p invalid qhandle in continuing exec query, conn:%p", (void*) pCont, pReadMsg->rpcMsg.handle);
       code = TSDB_CODE_QRY_INVALID_QHANDLE;
     } else {
       vDebug("vgId:%d, QInfo:%p, dnode continue exec query", pVnode->vgId, (void*) pCont);
-      code = TSDB_CODE_VND_ACTION_IN_PROGRESS;
-      qTableQuery(*handle); // do execute query
+
+      bool freehandle = false;
+      bool buildRes = qTableQuery(*handle); // do execute query
+
+      // build query rsp
+      if (buildRes) {
+        // update the connection info according to the retrieve connection
+        pReadMsg->rpcMsg.handle = qGetResultRetrieveMsg(*handle);
+        assert(pReadMsg->rpcMsg.handle != NULL);
+
+        vDebug("vgId:%d, QInfo:%p, start to build result rsp after query paused, %p", pVnode->vgId, *handle, pReadMsg->rpcMsg.handle);
+        code = vnodeDumpQueryResult(&pReadMsg->rspRet, pVnode, *handle, &freehandle);
+
+        // todo test the error code case
+        if (code == TSDB_CODE_SUCCESS) {
+          code = TSDB_CODE_QRY_HAS_RSP;
+        }
+      }
+
+      qReleaseQInfo(pVnode->qMgmt, (void**) &handle, freehandle);
     }
-    qReleaseQInfo(pVnode->qMgmt, (void**) &handle, false);
   }
 
   return code;
@@ -176,7 +228,7 @@ static int32_t vnodeProcessFetchMsg(SVnodeObj *pVnode, SReadMsg *pReadMsg) {
   pRetrieve->qhandle = htobe64(pRetrieve->qhandle);
   pRetrieve->free = htons(pRetrieve->free);
 
-  vDebug("vgId:%d, QInfo:%p, retrieve msg is disposed", pVnode->vgId, (void*) pRetrieve->qhandle);
+  vDebug("vgId:%d, QInfo:%p, retrieve msg is disposed, free:%d, conn:%p", pVnode->vgId, (void*) pRetrieve->qhandle, pRetrieve->free, pReadMsg->rpcMsg.handle);
 
   memset(pRet, 0, sizeof(SRspRet));
 
@@ -185,16 +237,8 @@ static int32_t vnodeProcessFetchMsg(SVnodeObj *pVnode, SReadMsg *pReadMsg) {
   if (handle == NULL || (*handle) != (void*) pRetrieve->qhandle) {
     code = TSDB_CODE_QRY_INVALID_QHANDLE;
     vDebug("vgId:%d, invalid qhandle in fetch result, QInfo:%p", pVnode->vgId, (void*) pRetrieve->qhandle);
-
-    pRet->rsp = (SRetrieveTableRsp *)rpcMallocCont(sizeof(SRetrieveTableRsp));
-    pRet->len = sizeof(SRetrieveTableRsp);
-
-    memset(pRet->rsp, 0, sizeof(SRetrieveTableRsp));
-    SRetrieveTableRsp* pRsp = pRet->rsp;
-    pRsp->numOfRows = 0;
-    pRsp->useconds  = 0;
-    pRsp->completed = true;
-
+    
+    vnodeBuildNoResultQueryRsp(pRet);
     return code;
   }
 
@@ -203,35 +247,25 @@ static int32_t vnodeProcessFetchMsg(SVnodeObj *pVnode, SReadMsg *pReadMsg) {
     qKillQuery(*handle);
     qReleaseQInfo(pVnode->qMgmt, (void**) &handle, true);
 
-    pRet->rsp = (SRetrieveTableRsp *)rpcMallocCont(sizeof(SRetrieveTableRsp));
-    pRet->len = sizeof(SRetrieveTableRsp);
-
-    memset(pRet->rsp, 0, sizeof(SRetrieveTableRsp));
-    SRetrieveTableRsp* pRsp = pRet->rsp;
-    pRsp->numOfRows = 0;
-    pRsp->completed = true;
-    pRsp->useconds  = 0;
-
+    vnodeBuildNoResultQueryRsp(pRet);
     return code;
   }
 
   bool freeHandle = true;
-  code = qRetrieveQueryResultInfo(*handle);
+  bool buildRes   = false;
+
+  code = qRetrieveQueryResultInfo(*handle, &buildRes, pReadMsg->rpcMsg.handle);
   if (code != TSDB_CODE_SUCCESS) {
     //TODO handle malloc failure
     pRet->rsp = (SRetrieveTableRsp *)rpcMallocCont(sizeof(SRetrieveTableRsp));
     memset(pRet->rsp, 0, sizeof(SRetrieveTableRsp));
-  } else { // if failed to dump result, free qhandle immediately
-    if ((code = qDumpRetrieveResult(*handle, (SRetrieveTableRsp **)&pRet->rsp, &pRet->len)) == TSDB_CODE_SUCCESS) {
-      if (qHasMoreResultsToRetrieve(*handle)) {
-        vnodePutItemIntoReadQueue(pVnode, *handle);
-        pRet->qhandle = *handle;
-        freeHandle = false;
-      } else {
-        qKillQuery(*handle);
-        freeHandle = true;
-      }
+  } else { // result is not ready, return immediately
+    if (!buildRes) {
+      qReleaseQInfo(pVnode->qMgmt, (void**) &handle, false);
+      return TSDB_CODE_QRY_NOT_READY;
     }
+
+    code = vnodeDumpQueryResult(pRet, pVnode, *handle, &freeHandle);
   }
 
   qReleaseQInfo(pVnode->qMgmt, (void**) &handle, freeHandle);

tests/script/general/parser/testSuite.sim

@@ -93,6 +93,8 @@ run general/parser/groupby.sim
 sleep 2000
 run general/parser/tags_filter.sim
 sleep 2000
+run general/parser/topbot.sim
+sleep 2000
 run general/parser/union.sim
 sleep 2000
 run general/parser/sliding.sim

tests/script/general/parser/topbot.sim

+system sh/stop_dnodes.sh
+
+system sh/deploy.sh -n dnode1 -i 1
+system sh/cfg.sh -n dnode1 -c walLevel -v 0
+system sh/exec.sh -n dnode1 -s start
+sleep 3000
+sql connect
+
+$dbPrefix = tb_db
+$tbPrefix = tb_tb
+$stbPrefix = tb_stb
+$tbNum = 10
+$rowNum = 1000
+$totalNum = $tbNum * $rowNum
+$loops = 200000
+$log = 10000
+$ts0 = 1537146000000
+$delta = 600000
+print ========== topbot.sim
+$i = 0
+$db = $dbPrefix . $i
+$stb = $stbPrefix . $i
+
+sql drop database $db -x step1
+step1:
+sql create database $db cache 16 maxtables 200
+print ====== create tables
+sql use $db
+sql create table $stb (ts timestamp, c1 int, c2 bigint, c3 float, c4 double, c5 smallint, c6 tinyint, c7 bool, c8 binary(10), c9 nchar(10)) tags(t1 int)
+
+$i = 0
+$ts = $ts0
+$halfNum = $tbNum / 2
+while $i < $halfNum
+  $tbId = $i + $halfNum
+  $tb = $tbPrefix . $i
+  $tb1 = $tbPrefix . $tbId
+  sql create table $tb using $stb tags( $i )
+  sql create table $tb1 using $stb tags( $tbId )
+
+  $x = 0
+  while $x < $rowNum
+    $xs = $x * $delta
+    $ts = $ts0 + $xs
+    $c = $x / 10
+    $c = $c * 10
+    $c = $x - $c
+    $binary = 'binary . $c
+    $binary = $binary . '
+    $nchar = 'nchar . $c
+    $nchar = $nchar . '
+    sql insert into $tb values ( $ts , $c , $c , $c , $c , $c , $c , true, $binary , $nchar )
+    sql insert into $tb1 values ( $ts , $c , NULL , $c , NULL , $c , $c , true, $binary , $nchar )
+    $x = $x + 1
+  endw
+
+  $i = $i + 1
+endw
+print ====== tables created
+
+sql use $db
+##### select from table
+print ====== select top/bot from table and check num of rows returned
+sql select top(c1, 100) from tb_stb0
+if $row != 100 then
+  return -1
+endi
+
+sql select last(c2) from tb_tb9
+if $row != 1 then
+  return -1
+endi
+
+system sh/exec.sh -n dnode1 -s stop -x SIGINT
\ No newline at end of file