From 3a0ea21342749f91c8e4d80a35c91c40b1e73c9e Mon Sep 17 00:00:00 2001
From: Minglei Jin <mljin@taosdata.com>
Date: Thu, 13 Oct 2022 19:54:25 +0800
Subject: [PATCH 01/24] fix: get SLastCol from array instead of SColVal

---
 source/dnode/vnode/src/tsdb/tsdbCache.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/source/dnode/vnode/src/tsdb/tsdbCache.c b/source/dnode/vnode/src/tsdb/tsdbCache.c
index ac6be9af2d..1615edb6ce 100644
--- a/source/dnode/vnode/src/tsdb/tsdbCache.c
+++ b/source/dnode/vnode/src/tsdb/tsdbCache.c
@@ -1189,7 +1189,8 @@ static int32_t mergeLast(tb_uid_t uid, STsdb *pTsdb, SArray **ppLastArray) {
     setNoneCol = false;
     for (iCol = noneCol; iCol < nCol; ++iCol) {
       // high version's column value
-      SColVal *tColVal = (SColVal *)taosArrayGet(pColArray, iCol);
+      SLastCol *lastColVal = (SLastCol *)taosArrayGet(pColArray, iCol);
+      SColVal  *tColVal = &lastColVal->colVal;
 
       tsdbRowGetColVal(pRow, pTSchema, iCol, pColVal);
       if (!COL_VAL_IS_VALUE(tColVal) && COL_VAL_IS_VALUE(pColVal)) {

From 977fc4b15cd93a1c7d5144e75237c5c3d4398ac5 Mon Sep 17 00:00:00 2001
From: Minglei Jin <mljin@taosdata.com>
Date: Fri, 14 Oct 2022 15:28:19 +0800
Subject: [PATCH 02/24] fix(tsdb/cache): release lock when table's empty

---
 source/dnode/vnode/src/tsdb/tsdbCache.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/source/dnode/vnode/src/tsdb/tsdbCache.c b/source/dnode/vnode/src/tsdb/tsdbCache.c
index 1615edb6ce..4088d35d3e 100644
--- a/source/dnode/vnode/src/tsdb/tsdbCache.c
+++ b/source/dnode/vnode/src/tsdb/tsdbCache.c
@@ -1311,6 +1311,8 @@ int32_t tsdbCacheGetLastH(SLRUCache *pCache, tb_uid_t uid, STsdb *pTsdb, LRUHand
       // if table's empty or error, return code of -1
       // if (code < 0 || pRow == NULL) {
       if (code < 0 || pLastArray == NULL) {
+        taosThreadMutexUnlock(&pTsdb->lruMutex);
+
         *handle = NULL;
         return 0;
       }

From b62fa20b53fd9640d92250ed59ce22e5e9821d3a Mon Sep 17 00:00:00 2001
From: Minglei Jin <mljin@taosdata.com>
Date: Mon, 17 Oct 2022 17:20:32 +0800
Subject: [PATCH 03/24] tsdb/cache: return last row as array of SLastCol

---
 source/dnode/vnode/src/tsdb/tsdbCache.c     | 122 ++++++++++++++------
 source/dnode/vnode/src/tsdb/tsdbCacheRead.c |   3 +-
 2 files changed, 91 insertions(+), 34 deletions(-)

diff --git a/source/dnode/vnode/src/tsdb/tsdbCache.c b/source/dnode/vnode/src/tsdb/tsdbCache.c
index 4088d35d3e..e27fc252a0 100644
--- a/source/dnode/vnode/src/tsdb/tsdbCache.c
+++ b/source/dnode/vnode/src/tsdb/tsdbCache.c
@@ -61,8 +61,6 @@ static void getTableCacheKey(tb_uid_t uid, int cacheType, char *key, int *len) {
   *len = sizeof(uint64_t);
 }
 
-static void deleteTableCacheLastrow(const void *key, size_t keyLen, void *value) { taosMemoryFree(value); }
-
 static void deleteTableCacheLast(const void *key, size_t keyLen, void *value) { taosArrayDestroy(value); }
 
 int32_t tsdbCacheDeleteLastrow(SLRUCache *pCache, tb_uid_t uid, TSKEY eKey) {
@@ -75,13 +73,23 @@ int32_t tsdbCacheDeleteLastrow(SLRUCache *pCache, tb_uid_t uid, TSKEY eKey) {
   getTableCacheKey(uid, 0, key, &keyLen);
   LRUHandle *h = taosLRUCacheLookup(pCache, key, keyLen);
   if (h) {
-    STSRow *pRow = (STSRow *)taosLRUCacheValue(pCache, h);
-    if (pRow->ts <= eKey) {
+    SArray *pLast = (SArray *)taosLRUCacheValue(pCache, h);
+    bool    invalidate = false;
+    int16_t nCol = taosArrayGetSize(pLast);
+
+    for (int16_t iCol = 0; iCol < nCol; ++iCol) {
+      SLastCol *tTsVal = (SLastCol *)taosArrayGet(pLast, iCol);
+      if (eKey >= tTsVal->ts) {
+        invalidate = true;
+        break;
+      }
+    }
+
+    if (invalidate) {
       taosLRUCacheRelease(pCache, h, true);
     } else {
       taosLRUCacheRelease(pCache, h, false);
     }
-
     // void taosLRUCacheErase(SLRUCache * cache, const void *key, size_t keyLen);
   }
 
@@ -130,14 +138,23 @@ int32_t tsdbCacheDelete(SLRUCache *pCache, tb_uid_t uid, TSKEY eKey) {
   getTableCacheKey(uid, 0, key, &keyLen);
   LRUHandle *h = taosLRUCacheLookup(pCache, key, keyLen);
   if (h) {
-    STSRow *pRow = (STSRow *)taosLRUCacheValue(pCache, h);
-    if (pRow->ts <= eKey) {
+    SArray *pLast = (SArray *)taosLRUCacheValue(pCache, h);
+    bool    invalidate = false;
+    int16_t nCol = taosArrayGetSize(pLast);
+
+    for (int16_t iCol = 0; iCol < nCol; ++iCol) {
+      SLastCol *tTsVal = (SLastCol *)taosArrayGet(pLast, iCol);
+      if (eKey >= tTsVal->ts) {
+        invalidate = true;
+        break;
+      }
+    }
+
+    if (invalidate) {
       taosLRUCacheRelease(pCache, h, true);
     } else {
       taosLRUCacheRelease(pCache, h, false);
     }
-
-    // void taosLRUCacheErase(SLRUCache * cache, const void *key, size_t keyLen);
   }
 
   // getTableCacheKey(uid, "l", key, &keyLen);
@@ -177,6 +194,46 @@ int32_t tsdbCacheInsertLastrow(SLRUCache *pCache, STsdb *pTsdb, tb_uid_t uid, ST
   getTableCacheKey(uid, 0, key, &keyLen);
   LRUHandle *h = taosLRUCacheLookup(pCache, key, keyLen);
   if (h) {
+    STSchema *pTSchema = metaGetTbTSchema(pTsdb->pVnode->pMeta, uid, -1, 1);
+    TSKEY     keyTs = row->ts;
+    bool      invalidate = false;
+
+    SArray *pLast = (SArray *)taosLRUCacheValue(pCache, h);
+    int16_t nCol = taosArrayGetSize(pLast);
+    int16_t iCol = 0;
+
+    SLastCol *tTsVal = (SLastCol *)taosArrayGet(pLast, iCol);
+    if (keyTs > tTsVal->ts) {
+      STColumn *pTColumn = &pTSchema->columns[0];
+      SColVal   tColVal = COL_VAL_VALUE(pTColumn->colId, pTColumn->type, (SValue){.val = keyTs});
+
+      taosArraySet(pLast, iCol, &(SLastCol){.ts = keyTs, .colVal = tColVal});
+    }
+
+    for (++iCol; iCol < nCol; ++iCol) {
+      SLastCol *tTsVal1 = (SLastCol *)taosArrayGet(pLast, iCol);
+      if (keyTs >= tTsVal1->ts) {
+        SColVal *tColVal = &tTsVal1->colVal;
+
+        SColVal colVal = {0};
+        tTSRowGetVal(row, pTSchema, iCol, &colVal);
+        if (!COL_VAL_IS_NONE(&colVal)) {
+          if (keyTs == tTsVal1->ts && !COL_VAL_IS_NONE(tColVal)) {
+            invalidate = true;
+
+            break;
+          }
+        } else {
+          taosArraySet(pLast, iCol, &(SLastCol){.ts = keyTs, .colVal = colVal});
+        }
+      }
+    }
+
+  _invalidate:
+    taosMemoryFreeClear(pTSchema);
+
+    taosLRUCacheRelease(pCache, h, invalidate);
+    /*
     cacheRow = (STSRow *)taosLRUCacheValue(pCache, h);
     if (row->ts >= cacheRow->ts) {
       if (row->ts == cacheRow->ts) {
@@ -218,9 +275,9 @@ int32_t tsdbCacheInsertLastrow(SLRUCache *pCache, STsdb *pTsdb, tb_uid_t uid, ST
         if (status != TAOS_LRU_STATUS_OK) {
           code = -1;
         }
-        /* tsdbCacheInsertLastrow(pCache, uid, row, dup); */
+        // tsdbCacheInsertLastrow(pCache, uid, row, dup);
       }
-    }
+    }*/
   } /*else {
     if (dup) {
       cacheRow = tdRowDup(row);
@@ -1031,7 +1088,7 @@ _err:
   return code;
 }
 
-static int32_t mergeLastRow(tb_uid_t uid, STsdb *pTsdb, bool *dup, STSRow **ppRow) {
+static int32_t mergeLastRow(tb_uid_t uid, STsdb *pTsdb, bool *dup, SArray **ppColArray) {
   int32_t code = 0;
 
   STSchema *pTSchema = metaGetTbTSchema(pTsdb->pVnode->pMeta, uid, -1, 1);
@@ -1055,12 +1112,14 @@ static int32_t mergeLastRow(tb_uid_t uid, STsdb *pTsdb, bool *dup, STSRow **ppRo
       break;
     }
 
+    TSKEY rowTs = TSDBROW_TS(pRow);
+
     if (lastRowTs == TSKEY_MAX) {
-      lastRowTs = TSDBROW_TS(pRow);
+      lastRowTs = rowTs;
       STColumn *pTColumn = &pTSchema->columns[0];
 
       *pColVal = COL_VAL_VALUE(pTColumn->colId, pTColumn->type, (SValue){.val = lastRowTs});
-      if (taosArrayPush(pColArray, pColVal) == NULL) {
+      if (taosArrayPush(pColArray, &(SLastCol){.ts = lastRowTs, .colVal = *pColVal}) == NULL) {
         code = TSDB_CODE_OUT_OF_MEMORY;
         goto _err;
       }
@@ -1068,7 +1127,7 @@ static int32_t mergeLastRow(tb_uid_t uid, STsdb *pTsdb, bool *dup, STSRow **ppRo
       for (iCol = 1; iCol < nCol; ++iCol) {
         tsdbRowGetColVal(pRow, pTSchema, iCol, pColVal);
 
-        if (taosArrayPush(pColArray, pColVal) == NULL) {
+        if (taosArrayPush(pColArray, &(SLastCol){.ts = lastRowTs, .colVal = *pColVal}) == NULL) {
           code = TSDB_CODE_OUT_OF_MEMORY;
           goto _err;
         }
@@ -1079,15 +1138,15 @@ static int32_t mergeLastRow(tb_uid_t uid, STsdb *pTsdb, bool *dup, STSRow **ppRo
         }
       }
       if (!setNoneCol) {
-        // goto build the result ts row
+        // done, goto return pColArray
         break;
       } else {
         continue;
       }
     }
 
-    if ((TSDBROW_TS(pRow) < lastRowTs)) {
-      // goto build the result ts row
+    if ((rowTs < lastRowTs)) {
+      // done, goto return pColArray
       break;
     }
 
@@ -1099,7 +1158,7 @@ static int32_t mergeLastRow(tb_uid_t uid, STsdb *pTsdb, bool *dup, STSRow **ppRo
 
       tsdbRowGetColVal(pRow, pTSchema, iCol, pColVal);
       if (COL_VAL_IS_NONE(tColVal) && !COL_VAL_IS_NONE(pColVal)) {
-        taosArraySet(pColArray, iCol, pColVal);
+        taosArraySet(pColArray, iCol, &(SLastCol){.ts = rowTs, .colVal = *pColVal});
       } else if (COL_VAL_IS_NONE(tColVal) && COL_VAL_IS_NONE(pColVal) && !setNoneCol) {
         noneCol = iCol;
         setNoneCol = true;
@@ -1110,14 +1169,13 @@ static int32_t mergeLastRow(tb_uid_t uid, STsdb *pTsdb, bool *dup, STSRow **ppRo
   // build the result ts row here
   *dup = false;
   if (taosArrayGetSize(pColArray) == nCol) {
-    code = tdSTSRowNew(pColArray, pTSchema, ppRow);
-    if (code) goto _err;
+    *ppColArray = NULL;
+    taosArrayDestroy(pColArray);
   } else {
-    *ppRow = NULL;
+    *ppColArray = pColArray;
   }
 
   nextRowIterClose(&iter);
-  taosArrayDestroy(pColArray);
   taosMemoryFreeClear(pTSchema);
   return code;
 
@@ -1178,7 +1236,7 @@ static int32_t mergeLast(tb_uid_t uid, STsdb *pTsdb, SArray **ppLastArray) {
         }
       }
       if (!setNoneCol) {
-        // goto build the result ts row
+        // done, goto return pColArray
         break;
       } else {
         continue;
@@ -1202,7 +1260,6 @@ static int32_t mergeLast(tb_uid_t uid, STsdb *pTsdb, SArray **ppLastArray) {
     }
   } while (setNoneCol);
 
-  // build the result ts row here
   if (taosArrayGetSize(pColArray) <= 0) {
     *ppLastArray = NULL;
     taosArrayDestroy(pColArray);
@@ -1233,13 +1290,13 @@ int32_t tsdbCacheGetLastrowH(SLRUCache *pCache, tb_uid_t uid, STsdb *pTsdb, LRUH
 
     h = taosLRUCacheLookup(pCache, key, keyLen);
     if (!h) {
-      STSRow *pRow = NULL;
+      SArray *pArray = NULL;
       bool    dup = false;  // which is always false for now
-      code = mergeLastRow(uid, pTsdb, &dup, &pRow);
+      code = mergeLastRow(uid, pTsdb, &dup, &pArray);
       // if table's empty or error, return code of -1
-      if (code < 0 || pRow == NULL) {
-        if (!dup && pRow) {
-          taosMemoryFree(pRow);
+      if (code < 0 || pArray == NULL) {
+        if (!dup && pArray) {
+          taosArrayDestroy(pArray);
         }
 
         taosThreadMutexUnlock(&pTsdb->lruMutex);
@@ -1249,9 +1306,9 @@ int32_t tsdbCacheGetLastrowH(SLRUCache *pCache, tb_uid_t uid, STsdb *pTsdb, LRUH
         return 0;
       }
 
-      _taos_lru_deleter_t deleter = deleteTableCacheLastrow;
+      _taos_lru_deleter_t deleter = deleteTableCacheLast;
       LRUStatus           status =
-          taosLRUCacheInsert(pCache, key, keyLen, pRow, TD_ROW_LEN(pRow), deleter, NULL, TAOS_LRU_PRIORITY_LOW);
+          taosLRUCacheInsert(pCache, key, keyLen, pArray, pArray->capacity, deleter, NULL, TAOS_LRU_PRIORITY_LOW);
       if (status != TAOS_LRU_STATUS_OK) {
         code = -1;
       }
@@ -1309,7 +1366,6 @@ int32_t tsdbCacheGetLastH(SLRUCache *pCache, tb_uid_t uid, STsdb *pTsdb, LRUHand
       SArray *pLastArray = NULL;
       code = mergeLast(uid, pTsdb, &pLastArray);
       // if table's empty or error, return code of -1
-      // if (code < 0 || pRow == NULL) {
       if (code < 0 || pLastArray == NULL) {
         taosThreadMutexUnlock(&pTsdb->lruMutex);
 
diff --git a/source/dnode/vnode/src/tsdb/tsdbCacheRead.c b/source/dnode/vnode/src/tsdb/tsdbCacheRead.c
index 81219e1442..d0d0563649 100644
--- a/source/dnode/vnode/src/tsdb/tsdbCacheRead.c
+++ b/source/dnode/vnode/src/tsdb/tsdbCacheRead.c
@@ -128,7 +128,8 @@ static int32_t doExtractCacheRow(SCacheRowsReader* pr, SLRUCache* lruCache, uint
 
     // no data in the table of Uid
     if (*h != NULL) {
-      *pRow = (STSRow*)taosLRUCacheValue(lruCache, *h);
+      //*pRow = (STSRow*)taosLRUCacheValue(lruCache, *h);
+      SArray* pLastrow = (SArray*)taosLRUCacheValue(lruCache, *h);
     }
   } else {
     code = tsdbCacheGetLastH(lruCache, uid, pr->pVnode->pTsdb, h);

From da9df994615e5fd6634c829ecf4d8076c729a493 Mon Sep 17 00:00:00 2001
From: Haojun Liao <hjliao@taosdata.com>
Date: Mon, 17 Oct 2022 17:59:43 +0800
Subject: [PATCH 04/24] fix(query): opt last query.

---
 include/common/tcommon.h                    | 21 +++++
 source/dnode/vnode/src/inc/tsdb.h           |  5 ++
 source/dnode/vnode/src/tsdb/tsdbCache.c     |  5 --
 source/dnode/vnode/src/tsdb/tsdbCacheRead.c | 97 +++++++++++++++++----
 source/libs/function/src/builtinsimpl.c     | 21 -----
 5 files changed, 106 insertions(+), 43 deletions(-)

diff --git a/include/common/tcommon.h b/include/common/tcommon.h
index eaddf4e983..c32fe81335 100644
--- a/include/common/tcommon.h
+++ b/include/common/tcommon.h
@@ -78,6 +78,27 @@ typedef struct {
   int32_t  exprIdx;
 } STupleKey;
 
+typedef struct STuplePos {
+  union {
+    struct {
+      int32_t pageId;
+      int32_t offset;
+    };
+    STupleKey streamTupleKey;
+  };
+} STuplePos;
+
+typedef struct SFirstLastRes {
+  bool hasResult;
+  // used for last_row function only, isNullRes in SResultRowEntry can not be passed to downstream.So,
+  // this attribute is required
+  bool      isNull;
+  int32_t   bytes;
+  int64_t   ts;
+  STuplePos pos;
+  char      buf[];
+} SFirstLastRes;
+
 static inline int STupleKeyCmpr(const void* pKey1, int kLen1, const void* pKey2, int kLen2) {
   STupleKey* pTuple1 = (STupleKey*)pKey1;
   STupleKey* pTuple2 = (STupleKey*)pKey2;
diff --git a/source/dnode/vnode/src/inc/tsdb.h b/source/dnode/vnode/src/inc/tsdb.h
index bf110f1ae3..91761663e8 100644
--- a/source/dnode/vnode/src/inc/tsdb.h
+++ b/source/dnode/vnode/src/inc/tsdb.h
@@ -306,6 +306,11 @@ int32_t tsdbMerge(STsdb *pTsdb);
 #define TSDB_CACHE_LAST(c)     (((c).cacheLast & 2) > 0)
 
 // tsdbCache ==============================================================================================
+typedef struct {
+  TSKEY   ts;
+  SColVal colVal;
+} SLastCol;
+
 int32_t tsdbOpenCache(STsdb *pTsdb);
 void    tsdbCloseCache(STsdb *pTsdb);
 int32_t tsdbCacheInsertLast(SLRUCache *pCache, tb_uid_t uid, STSRow *row, STsdb *pTsdb);
diff --git a/source/dnode/vnode/src/tsdb/tsdbCache.c b/source/dnode/vnode/src/tsdb/tsdbCache.c
index de26df6c54..b5624db51c 100644
--- a/source/dnode/vnode/src/tsdb/tsdbCache.c
+++ b/source/dnode/vnode/src/tsdb/tsdbCache.c
@@ -15,11 +15,6 @@
 
 #include "tsdb.h"
 
-typedef struct {
-  TSKEY   ts;
-  SColVal colVal;
-} SLastCol;
-
 int32_t tsdbOpenCache(STsdb *pTsdb) {
   int32_t    code = 0;
   SLRUCache *pCache = NULL;
diff --git a/source/dnode/vnode/src/tsdb/tsdbCacheRead.c b/source/dnode/vnode/src/tsdb/tsdbCacheRead.c
index d0d0563649..2d4a1b54cd 100644
--- a/source/dnode/vnode/src/tsdb/tsdbCacheRead.c
+++ b/source/dnode/vnode/src/tsdb/tsdbCacheRead.c
@@ -29,7 +29,7 @@ typedef struct SCacheRowsReader {
   SArray*   pTableList;  // table id list
 } SCacheRowsReader;
 
-static void saveOneRow(STSRow* pRow, SSDataBlock* pBlock, SCacheRowsReader* pReader, const int32_t* slotIds) {
+static void saveOneRow(SArray* pRow, SSDataBlock* pBlock, SCacheRowsReader* pReader, const int32_t* slotIds) {
   ASSERT(pReader->numOfCols <= taosArrayGetSize(pBlock->pDataBlock));
   int32_t numOfRows = pBlock->info.rows;
 
@@ -37,20 +37,35 @@ static void saveOneRow(STSRow* pRow, SSDataBlock* pBlock, SCacheRowsReader* pRea
   for (int32_t i = 0; i < pReader->numOfCols; ++i) {
     SColumnInfoData* pColInfoData = taosArrayGet(pBlock->pDataBlock, i);
 
+    SFirstLastRes *pRes = taosMemoryCalloc(1, sizeof(SFirstLastRes) + TSDB_KEYSIZE);
+    SLastCol *pColVal = (SLastCol *)taosArrayGet(pRow, i);
+
     if (slotIds[i] == -1) {
-      colDataAppend(pColInfoData, numOfRows, (const char*)&pRow->ts, false);
+      pRes->ts = pColVal->ts;
+      pRes->bytes = TSDB_KEYSIZE;
+      pRes->isNull = false;
+      pRes->hasResult = true;
+
+      colDataAppend(pColInfoData, numOfRows, (const char*)pRes, false);
     } else {
       int32_t slotId = slotIds[i];
 
-      tTSRowGetVal(pRow, pReader->pSchema, slotId, &colVal);
+      int32_t bytes = pReader->pSchema->columns[slotId].bytes;
+      pRes = taosMemoryCalloc(1, sizeof(SFirstLastRes) + bytes);
+      pRes->bytes = bytes;
+      pRes->hasResult = true;
 
       if (IS_VAR_DATA_TYPE(colVal.type)) {
         if (!COL_VAL_IS_VALUE(&colVal)) {
-          colDataAppendNULL(pColInfoData, numOfRows);
+          pRes->isNull = true;
+          pRes->ts = pColVal->ts;
+
+          colDataAppend(pColInfoData, numOfRows, (const char*)pRes, false);
         } else {
-          varDataSetLen(pReader->transferBuf[slotId], colVal.value.nData);
-          memcpy(varDataVal(pReader->transferBuf[slotId]), colVal.value.pData, colVal.value.nData);
-          colDataAppend(pColInfoData, numOfRows, pReader->transferBuf[slotId], false);
+          varDataSetLen(pRes->buf, colVal.value.nData);
+          memcpy(varDataVal(pRes->buf), colVal.value.pData, colVal.value.nData);
+          pRes->bytes = colVal.value.nData;
+          colDataAppend(pColInfoData, numOfRows, (const char*)pRes, false);
         }
       } else {
         colDataAppend(pColInfoData, numOfRows, (const char*)&colVal.value, !COL_VAL_IS_VALUE(&colVal));
@@ -117,7 +132,7 @@ void* tsdbCacherowsReaderClose(void* pReader) {
   return NULL;
 }
 
-static int32_t doExtractCacheRow(SCacheRowsReader* pr, SLRUCache* lruCache, uint64_t uid, STSRow** pRow,
+static int32_t doExtractCacheRow(SCacheRowsReader* pr, SLRUCache* lruCache, uint64_t uid, SArray** pRow,
                                  LRUHandle** h) {
   int32_t code = TSDB_CODE_SUCCESS;
   if ((pr->type & CACHESCAN_RETRIEVE_LAST_ROW) == CACHESCAN_RETRIEVE_LAST_ROW) {
@@ -127,9 +142,8 @@ static int32_t doExtractCacheRow(SCacheRowsReader* pr, SLRUCache* lruCache, uint
     }
 
     // no data in the table of Uid
-    if (*h != NULL) {
-      //*pRow = (STSRow*)taosLRUCacheValue(lruCache, *h);
-      SArray* pLastrow = (SArray*)taosLRUCacheValue(lruCache, *h);
+    if (*h != NULL) {  // todo convert to SArray
+      *pRow = (SArray*)taosLRUCacheValue(lruCache, *h);
     }
   } else {
     code = tsdbCacheGetLastH(lruCache, uid, pr->pVnode->pTsdb, h);
@@ -139,8 +153,7 @@ static int32_t doExtractCacheRow(SCacheRowsReader* pr, SLRUCache* lruCache, uint
 
     // no data in the table of Uid
     if (*h != NULL) {
-      SArray* pLast = (SArray*)taosLRUCacheValue(lruCache, *h);
-      tsdbCacheLastArray2Row(pLast, pRow, pr->pSchema);
+      *pRow = (SArray*)taosLRUCacheValue(lruCache, *h);
     }
   }
 
@@ -157,13 +170,17 @@ int32_t tsdbRetrieveCacheRows(void* pReader, SSDataBlock* pResBlock, const int32
   int32_t    code = TSDB_CODE_SUCCESS;
   SLRUCache* lruCache = pr->pVnode->pTsdb->lruCache;
   LRUHandle* h = NULL;
-  STSRow*    pRow = NULL;
+  SArray*    pRow = NULL;
   size_t     numOfTables = taosArrayGetSize(pr->pTableList);
 
+  int64_t* lastTs = taosMemoryMalloc(TSDB_KEYSIZE * pr->pSchema->numOfCols);
+  for(int32_t i = 0; i < pr->pSchema->numOfCols; ++i) {
+    lastTs[i] = INT64_MIN;
+  }
+
   // retrieve the only one last row of all tables in the uid list.
   if ((pr->type & CACHESCAN_RETRIEVE_TYPE_SINGLE) == CACHESCAN_RETRIEVE_TYPE_SINGLE) {
-    int64_t lastKey = INT64_MIN;
-    bool    internalResult = false;
+    bool internalResult = false;
     for (int32_t i = 0; i < numOfTables; ++i) {
       STableKeyInfo* pKeyInfo = taosArrayGet(pr->pTableList, i);
 
@@ -176,7 +193,53 @@ int32_t tsdbRetrieveCacheRows(void* pReader, SSDataBlock* pResBlock, const int32
         continue;
       }
 
+      {
+        SFirstLastRes** pRes = taosMemoryCalloc(pr->numOfCols, POINTER_BYTES);
+        for(int32_t j = 0; j < pr->numOfCols; ++j) {
+          pRes[j] = taosMemoryCalloc(1, sizeof(SFirstLastRes) + pr->pSchema->columns[slotIds[j]].bytes);
+          pRes[j]->ts = INT64_MIN;
+        }
+
+        for (int32_t k = 0; k < pr->numOfCols; ++k) {
+          SColumnInfoData* pColInfoData = taosArrayGet(pResBlock->pDataBlock, k);
+
+          if (slotIds[k] == -1) { // the primary timestamp
+            SLastCol *pColVal = (SLastCol *)taosArrayGet(pRow, k);
+            if (pColVal->ts > pRes[k]->ts || !pRes[k]->hasResult) {
+              pRes[k]->hasResult = true;
+              pRes[k]->ts = pColVal->ts;
+              memcpy(pRes[k]->buf, &pColVal->ts, TSDB_KEYSIZE);
+
+              colDataAppend(pColInfoData, 1, (const char*)pRes[k], false);
+            }
+          } else {
+            int32_t   slotId = slotIds[k];
+            SLastCol* pColVal = (SLastCol*)taosArrayGet(pRow, slotId);
+
+            if (pColVal->ts > pRes[k]->ts || !pRes[k]->hasResult) {
+              pRes[k]->hasResult = true;
+              pRes[k]->ts = pColVal->ts;
+
+              pRes[k]->isNull = !COL_VAL_IS_VALUE(&pColVal->colVal);
+              if (!pRes[k]->isNull) {
+                if (IS_VAR_DATA_TYPE(pColVal->colVal.type)) {
+                  varDataSetLen(pRes[k]->buf, pColVal->colVal.value.nData);
+                  memcpy(varDataVal(pRes[k]->buf), pColVal->colVal.value.pData, pColVal->colVal.value.nData);
+                } else {
+                  memcpy(pRes[k]->buf, &pColVal->colVal.value, pr->pSchema->columns[slotId].bytes);
+                }
+              }
+
+              colDataAppend(pColInfoData, 1, (const char*)pRes[k], false);
+            }
+          }
+        }
+      }
+
+/*
       if (pRow->ts > lastKey) {
+        printf("qualified:%ld, old Value:%ld\n", pRow->ts, lastKey);
+
         // Set result row into the same rowIndex repeatly, so we need to check if the internal result row has already
         // appended or not.
         if (internalResult) {
@@ -189,7 +252,7 @@ int32_t tsdbRetrieveCacheRows(void* pReader, SSDataBlock* pResBlock, const int32
         internalResult = true;
         lastKey = pRow->ts;
       }
-
+*/
       tsdbCacheRelease(lruCache, h);
     }
   } else if ((pr->type & CACHESCAN_RETRIEVE_TYPE_ALL) == CACHESCAN_RETRIEVE_TYPE_ALL) {
diff --git a/source/libs/function/src/builtinsimpl.c b/source/libs/function/src/builtinsimpl.c
index 7077a9b780..493561ca1e 100644
--- a/source/libs/function/src/builtinsimpl.c
+++ b/source/libs/function/src/builtinsimpl.c
@@ -57,16 +57,6 @@ typedef struct SAvgRes {
   int16_t type;  // store the original input type, used in merge function
 } SAvgRes;
 
-typedef struct STuplePos {
-  union {
-    struct {
-      int32_t pageId;
-      int32_t offset;
-    };
-    STupleKey streamTupleKey;
-  };
-} STuplePos;
-
 typedef struct SMinmaxResInfo {
   bool      assign;  // assign the first value or not
   int64_t   v;
@@ -93,17 +83,6 @@ typedef struct STopBotRes {
   STopBotResItem* pItems;
 } STopBotRes;
 
-typedef struct SFirstLastRes {
-  bool hasResult;
-  // used for last_row function only, isNullRes in SResultRowEntry can not be passed to downstream.So,
-  // this attribute is required
-  bool      isNull;
-  int32_t   bytes;
-  int64_t   ts;
-  STuplePos pos;
-  char      buf[];
-} SFirstLastRes;
-
 typedef struct SStddevRes {
   double  result;
   int64_t count;

From 109d50a4cc7af9cb0e5decef9b8b47a2b1f96850 Mon Sep 17 00:00:00 2001
From: Minglei Jin <mljin@taosdata.com>
Date: Mon, 17 Oct 2022 18:13:38 +0800
Subject: [PATCH 05/24] fix: last row array form bug

---
 source/dnode/vnode/src/tsdb/tsdbCache.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/source/dnode/vnode/src/tsdb/tsdbCache.c b/source/dnode/vnode/src/tsdb/tsdbCache.c
index b5624db51c..f67a5cc444 100644
--- a/source/dnode/vnode/src/tsdb/tsdbCache.c
+++ b/source/dnode/vnode/src/tsdb/tsdbCache.c
@@ -1181,7 +1181,7 @@ static int32_t mergeLastRow(tb_uid_t uid, STsdb *pTsdb, bool *dup, SArray **ppCo
 
   // build the result ts row here
   *dup = false;
-  if (taosArrayGetSize(pColArray) == nCol) {
+  if (taosArrayGetSize(pColArray) != nCol) {
     *ppColArray = NULL;
     taosArrayDestroy(pColArray);
   } else {

From c8b180b129cf0155884c78d3e88762bd987aaf21 Mon Sep 17 00:00:00 2001
From: Haojun Liao <hjliao@taosdata.com>
Date: Mon, 17 Oct 2022 19:14:06 +0800
Subject: [PATCH 06/24] fix(query): update the cached last query.

---
 source/dnode/vnode/src/tsdb/tsdbCacheRead.c   | 97 +++++++------------
 source/libs/executor/src/cachescanoperator.c  |  1 +
 source/libs/executor/src/timewindowoperator.c | 28 +++---
 source/libs/function/src/builtins.c           |  2 +-
 source/libs/function/src/builtinsimpl.c       | 93 ------------------
 5 files changed, 54 insertions(+), 167 deletions(-)

diff --git a/source/dnode/vnode/src/tsdb/tsdbCacheRead.c b/source/dnode/vnode/src/tsdb/tsdbCacheRead.c
index 2d4a1b54cd..be36848fec 100644
--- a/source/dnode/vnode/src/tsdb/tsdbCacheRead.c
+++ b/source/dnode/vnode/src/tsdb/tsdbCacheRead.c
@@ -29,48 +29,37 @@ typedef struct SCacheRowsReader {
   SArray*   pTableList;  // table id list
 } SCacheRowsReader;
 
-static void saveOneRow(SArray* pRow, SSDataBlock* pBlock, SCacheRowsReader* pReader, const int32_t* slotIds) {
+static void saveOneRow(SArray* pRow, SSDataBlock* pBlock, SCacheRowsReader* pReader, const int32_t* slotIds,
+                       SFirstLastRes** pRes) {
   ASSERT(pReader->numOfCols <= taosArrayGetSize(pBlock->pDataBlock));
   int32_t numOfRows = pBlock->info.rows;
 
-  SColVal colVal = {0};
   for (int32_t i = 0; i < pReader->numOfCols; ++i) {
     SColumnInfoData* pColInfoData = taosArrayGet(pBlock->pDataBlock, i);
 
-    SFirstLastRes *pRes = taosMemoryCalloc(1, sizeof(SFirstLastRes) + TSDB_KEYSIZE);
-    SLastCol *pColVal = (SLastCol *)taosArrayGet(pRow, i);
-
-    if (slotIds[i] == -1) {
-      pRes->ts = pColVal->ts;
-      pRes->bytes = TSDB_KEYSIZE;
-      pRes->isNull = false;
-      pRes->hasResult = true;
-
-      colDataAppend(pColInfoData, numOfRows, (const char*)pRes, false);
+    if (slotIds[i] == -1) {  // the primary timestamp
+      SLastCol* pColVal = (SLastCol*)taosArrayGet(pRow, 0);
+      pRes[i]->ts = pColVal->ts;
+      memcpy(pRes[i]->buf, &pColVal->ts, TSDB_KEYSIZE);
     } else {
-      int32_t slotId = slotIds[i];
+      int32_t   slotId = slotIds[i];
+      SLastCol* pColVal = (SLastCol*)taosArrayGet(pRow, slotId);
 
-      int32_t bytes = pReader->pSchema->columns[slotId].bytes;
-      pRes = taosMemoryCalloc(1, sizeof(SFirstLastRes) + bytes);
-      pRes->bytes = bytes;
-      pRes->hasResult = true;
+      pRes[i]->ts = pColVal->ts;
+      pRes[i]->isNull = !COL_VAL_IS_VALUE(&pColVal->colVal);
 
-      if (IS_VAR_DATA_TYPE(colVal.type)) {
-        if (!COL_VAL_IS_VALUE(&colVal)) {
-          pRes->isNull = true;
-          pRes->ts = pColVal->ts;
-
-          colDataAppend(pColInfoData, numOfRows, (const char*)pRes, false);
+      if (!pRes[i]->isNull) {
+        if (IS_VAR_DATA_TYPE(pColVal->colVal.type)) {
+          varDataSetLen(pRes[i]->buf, pColVal->colVal.value.nData);
+          memcpy(varDataVal(pRes[i]->buf), pColVal->colVal.value.pData, pColVal->colVal.value.nData);
         } else {
-          varDataSetLen(pRes->buf, colVal.value.nData);
-          memcpy(varDataVal(pRes->buf), colVal.value.pData, colVal.value.nData);
-          pRes->bytes = colVal.value.nData;
-          colDataAppend(pColInfoData, numOfRows, (const char*)pRes, false);
+          memcpy(pRes[i]->buf, &pColVal->colVal.value, pReader->pSchema->columns[slotId].bytes);
         }
-      } else {
-        colDataAppend(pColInfoData, numOfRows, (const char*)&colVal.value, !COL_VAL_IS_VALUE(&colVal));
       }
     }
+
+    pRes[i]->hasResult = true;
+    colDataAppend(pColInfoData, numOfRows, (const char*)pRes[i], false);
   }
 
   pBlock->info.rows += 1;
@@ -142,7 +131,7 @@ static int32_t doExtractCacheRow(SCacheRowsReader* pr, SLRUCache* lruCache, uint
     }
 
     // no data in the table of Uid
-    if (*h != NULL) {  // todo convert to SArray
+    if (*h != NULL) {
       *pRow = (SArray*)taosLRUCacheValue(lruCache, *h);
     }
   } else {
@@ -172,15 +161,16 @@ int32_t tsdbRetrieveCacheRows(void* pReader, SSDataBlock* pResBlock, const int32
   LRUHandle* h = NULL;
   SArray*    pRow = NULL;
   size_t     numOfTables = taosArrayGetSize(pr->pTableList);
+  bool       hasRes = false;
 
-  int64_t* lastTs = taosMemoryMalloc(TSDB_KEYSIZE * pr->pSchema->numOfCols);
-  for(int32_t i = 0; i < pr->pSchema->numOfCols; ++i) {
-    lastTs[i] = INT64_MIN;
+  SFirstLastRes** pRes = taosMemoryCalloc(pr->numOfCols, POINTER_BYTES);
+  for (int32_t j = 0; j < pr->numOfCols; ++j) {
+    pRes[j] = taosMemoryCalloc(1, sizeof(SFirstLastRes) + pr->pSchema->columns[slotIds[j]].bytes);
+    pRes[j]->ts = INT64_MIN;
   }
 
   // retrieve the only one last row of all tables in the uid list.
   if ((pr->type & CACHESCAN_RETRIEVE_TYPE_SINGLE) == CACHESCAN_RETRIEVE_TYPE_SINGLE) {
-    bool internalResult = false;
     for (int32_t i = 0; i < numOfTables; ++i) {
       STableKeyInfo* pKeyInfo = taosArrayGet(pr->pTableList, i);
 
@@ -194,18 +184,13 @@ int32_t tsdbRetrieveCacheRows(void* pReader, SSDataBlock* pResBlock, const int32
       }
 
       {
-        SFirstLastRes** pRes = taosMemoryCalloc(pr->numOfCols, POINTER_BYTES);
-        for(int32_t j = 0; j < pr->numOfCols; ++j) {
-          pRes[j] = taosMemoryCalloc(1, sizeof(SFirstLastRes) + pr->pSchema->columns[slotIds[j]].bytes);
-          pRes[j]->ts = INT64_MIN;
-        }
-
         for (int32_t k = 0; k < pr->numOfCols; ++k) {
           SColumnInfoData* pColInfoData = taosArrayGet(pResBlock->pDataBlock, k);
 
-          if (slotIds[k] == -1) { // the primary timestamp
-            SLastCol *pColVal = (SLastCol *)taosArrayGet(pRow, k);
+          if (slotIds[k] == -1) {  // the primary timestamp
+            SLastCol* pColVal = (SLastCol*)taosArrayGet(pRow, k);
             if (pColVal->ts > pRes[k]->ts || !pRes[k]->hasResult) {
+              hasRes = true;
               pRes[k]->hasResult = true;
               pRes[k]->ts = pColVal->ts;
               memcpy(pRes[k]->buf, &pColVal->ts, TSDB_KEYSIZE);
@@ -217,6 +202,7 @@ int32_t tsdbRetrieveCacheRows(void* pReader, SSDataBlock* pResBlock, const int32
             SLastCol* pColVal = (SLastCol*)taosArrayGet(pRow, slotId);
 
             if (pColVal->ts > pRes[k]->ts || !pRes[k]->hasResult) {
+              hasRes = true;
               pRes[k]->hasResult = true;
               pRes[k]->ts = pColVal->ts;
 
@@ -236,25 +222,13 @@ int32_t tsdbRetrieveCacheRows(void* pReader, SSDataBlock* pResBlock, const int32
         }
       }
 
-/*
-      if (pRow->ts > lastKey) {
-        printf("qualified:%ld, old Value:%ld\n", pRow->ts, lastKey);
-
-        // Set result row into the same rowIndex repeatly, so we need to check if the internal result row has already
-        // appended or not.
-        if (internalResult) {
-          pResBlock->info.rows -= 1;
-          taosArrayClear(pTableUidList);
-        }
-
-        saveOneRow(pRow, pResBlock, pr, slotIds);
-        taosArrayPush(pTableUidList, &pKeyInfo->uid);
-        internalResult = true;
-        lastKey = pRow->ts;
-      }
-*/
       tsdbCacheRelease(lruCache, h);
     }
+
+    if (hasRes) {
+      pResBlock->info.rows = 1;
+    }
+
   } else if ((pr->type & CACHESCAN_RETRIEVE_TYPE_ALL) == CACHESCAN_RETRIEVE_TYPE_ALL) {
     for (int32_t i = pr->tableIndex; i < numOfTables; ++i) {
       STableKeyInfo* pKeyInfo = taosArrayGet(pr->pTableList, i);
@@ -267,9 +241,10 @@ int32_t tsdbRetrieveCacheRows(void* pReader, SSDataBlock* pResBlock, const int32
         continue;
       }
 
-      saveOneRow(pRow, pResBlock, pr, slotIds);
-      taosArrayPush(pTableUidList, &pKeyInfo->uid);
+      saveOneRow(pRow, pResBlock, pr, slotIds, pRes);
+      // TODO reset the pRes
 
+      taosArrayPush(pTableUidList, &pKeyInfo->uid);
       tsdbCacheRelease(lruCache, h);
 
       pr->tableIndex += 1;
diff --git a/source/libs/executor/src/cachescanoperator.c b/source/libs/executor/src/cachescanoperator.c
index 6106544a35..5d63892b7b 100644
--- a/source/libs/executor/src/cachescanoperator.c
+++ b/source/libs/executor/src/cachescanoperator.c
@@ -193,6 +193,7 @@ SSDataBlock* doScanCache(SOperatorInfo* pOperator) {
       pInfo->currentGroupIndex += 1;
 
       // check for tag values
+      // TODO NOTE: The uid of pInfo->pRes is required.
       if (pInfo->pRes->info.rows > 0) {
         if (pInfo->pseudoExprSup.numOfExprs > 0) {
           SExprSupp* pSup = &pInfo->pseudoExprSup;
diff --git a/source/libs/executor/src/timewindowoperator.c b/source/libs/executor/src/timewindowoperator.c
index c1478bc935..9c219d2765 100644
--- a/source/libs/executor/src/timewindowoperator.c
+++ b/source/libs/executor/src/timewindowoperator.c
@@ -1420,8 +1420,9 @@ static void doDeleteWindows(SOperatorInfo* pOperator, SInterval* pInterval, SSDa
   SColumnInfoData*             pGpCol = taosArrayGet(pBlock->pDataBlock, GROUPID_COLUMN_INDEX);
   uint64_t*                    pGpDatas = (uint64_t*)pGpCol->pData;
   for (int32_t i = 0; i < pBlock->info.rows; i++) {
-    SResultRowInfo dumyInfo;
+    SResultRowInfo dumyInfo = {0};
     dumyInfo.cur.pageId = -1;
+
     STimeWindow win = {0};
     if (IS_FINAL_OP(pInfo)) {
       win.skey = startTsCols[i];
@@ -5828,27 +5829,30 @@ SOperatorInfo* createStreamIntervalOperatorInfo(SOperatorInfo* downstream, SPhys
   pInfo->ignoreExpiredData = pIntervalPhyNode->window.igExpired;
   pInfo->isFinal = false;
 
-  if (pIntervalPhyNode->window.pExprs != NULL) {
-    int32_t    numOfScalar = 0;
-    SExprInfo* pScalarExprInfo = createExprInfo(pIntervalPhyNode->window.pExprs, NULL, &numOfScalar);
-    int32_t    code = initExprSupp(&pInfo->scalarSupp, pScalarExprInfo, numOfScalar);
-    if (code != TSDB_CODE_SUCCESS) {
-      goto _error;
-    }
-  }
+
 
   pInfo->primaryTsIndex = ((SColumnNode*)pIntervalPhyNode->window.pTspk)->slotId;
   initResultSizeInfo(&pOperator->resultInfo, 4096);
   SExprSupp* pSup = &pOperator->exprSupp;
+
+  initBasicInfo(&pInfo->binfo, pResBlock);
+  initStreamFunciton(pSup->pCtx, pSup->numOfExprs);
+  initExecTimeWindowInfo(&pInfo->twAggSup.timeWindowData, &pTaskInfo->window);
+
   size_t     keyBufSize = sizeof(int64_t) + sizeof(int64_t) + POINTER_BYTES;
   int32_t    code = initAggInfo(pSup, &pInfo->aggSup, pExprInfo, numOfCols, keyBufSize, pTaskInfo->id.str);
   if (code != TSDB_CODE_SUCCESS) {
     goto _error;
   }
 
-  initBasicInfo(&pInfo->binfo, pResBlock);
-  initStreamFunciton(pSup->pCtx, pSup->numOfExprs);
-  initExecTimeWindowInfo(&pInfo->twAggSup.timeWindowData, &pTaskInfo->window);
+  if (pIntervalPhyNode->window.pExprs != NULL) {
+    int32_t    numOfScalar = 0;
+    SExprInfo* pScalarExprInfo = createExprInfo(pIntervalPhyNode->window.pExprs, NULL, &numOfScalar);
+    code = initExprSupp(&pInfo->scalarSupp, pScalarExprInfo, numOfScalar);
+    if (code != TSDB_CODE_SUCCESS) {
+      goto _error;
+    }
+  }
 
   pInfo->invertible = allInvertible(pSup->pCtx, numOfCols);
   pInfo->invertible = false;
diff --git a/source/libs/function/src/builtins.c b/source/libs/function/src/builtins.c
index 2308aaf214..54e8c27d5b 100644
--- a/source/libs/function/src/builtins.c
+++ b/source/libs/function/src/builtins.c
@@ -2402,7 +2402,7 @@ const SBuiltinFuncDefinition funcMgtBuiltins[] = {
     .translateFunc = translateFirstLast,
     .getEnvFunc   = getFirstLastFuncEnv,
     .initFunc     = functionSetup,
-    .processFunc  = cachedLastRowFunction,
+    .processFunc  = lastFunctionMerge,
     .finalizeFunc = firstLastFinalize
   },
   {
diff --git a/source/libs/function/src/builtinsimpl.c b/source/libs/function/src/builtinsimpl.c
index 493561ca1e..3255ef7d26 100644
--- a/source/libs/function/src/builtinsimpl.c
+++ b/source/libs/function/src/builtinsimpl.c
@@ -6148,99 +6148,6 @@ int32_t groupKeyFinalize(SqlFunctionCtx* pCtx, SSDataBlock* pBlock) {
   return pResInfo->numOfRes;
 }
 
-int32_t interpFunction(SqlFunctionCtx* pCtx) {
-#if 0
-  int32_t fillType = (int32_t) pCtx->param[2].i64;
-  //bool ascQuery = (pCtx->order == TSDB_ORDER_ASC);
-
-  if (pCtx->start.key == pCtx->startTs) {
-    assert(pCtx->start.key != INT64_MIN);
-
-    COPY_TYPED_DATA(pCtx->pOutput, pCtx->inputType, &pCtx->start.val);
-
-    goto interp_success_exit;
-  } else if (pCtx->end.key == pCtx->startTs && pCtx->end.key != INT64_MIN && fillType == TSDB_FILL_NEXT) {
-    COPY_TYPED_DATA(pCtx->pOutput, pCtx->inputType, &pCtx->end.val);
-
-    goto interp_success_exit;
-  }
-
-  switch (fillType) {
-    case TSDB_FILL_NULL:
-      setNull(pCtx->pOutput, pCtx->outputType, pCtx->outputBytes);
-      break;
-
-    case TSDB_FILL_SET_VALUE:
-      tVariantDump(&pCtx->param[1], pCtx->pOutput, pCtx->inputType, true);
-      break;
-
-    case TSDB_FILL_LINEAR:
-      if (pCtx->start.key == INT64_MIN || pCtx->start.key > pCtx->startTs
-          || pCtx->end.key == INT64_MIN || pCtx->end.key < pCtx->startTs) {
-        goto interp_exit;
-      }
-
-      double v1 = -1, v2 = -1;
-      GET_TYPED_DATA(v1, double, pCtx->inputType, &pCtx->start.val);
-      GET_TYPED_DATA(v2, double, pCtx->inputType, &pCtx->end.val);
-
-      SPoint point1 = {.key = pCtx->start.key, .val = &v1};
-      SPoint point2 = {.key = pCtx->end.key, .val = &v2};
-      SPoint point  = {.key = pCtx->startTs, .val = pCtx->pOutput};
-
-      int32_t srcType = pCtx->inputType;
-      if (isNull((char *)&pCtx->start.val, srcType) || isNull((char *)&pCtx->end.val, srcType)) {
-        setNull(pCtx->pOutput, srcType, pCtx->inputBytes);
-      } else {
-        bool exceedMax = false, exceedMin = false;
-        taosGetLinearInterpolationVal(&point, pCtx->outputType, &point1, &point2, TSDB_DATA_TYPE_DOUBLE, &exceedMax, &exceedMin);
-        if (exceedMax || exceedMin) {
-          __compar_fn_t func = getComparFunc((int32_t)pCtx->inputType, 0);
-          if (func(&pCtx->start.val, &pCtx->end.val) <= 0) {
-            COPY_TYPED_DATA(pCtx->pOutput, pCtx->inputType, exceedMax ? &pCtx->start.val : &pCtx->end.val);
-          } else {
-            COPY_TYPED_DATA(pCtx->pOutput, pCtx->inputType, exceedMax ? &pCtx->end.val : &pCtx->start.val);
-          }
-        }
-      }
-      break;
-
-    case TSDB_FILL_PREV:
-      if (pCtx->start.key == INT64_MIN || pCtx->start.key > pCtx->startTs) {
-        goto interp_exit;
-      }
-
-      COPY_TYPED_DATA(pCtx->pOutput, pCtx->inputType, &pCtx->start.val);
-      break;
-
-    case TSDB_FILL_NEXT:
-      if (pCtx->end.key == INT64_MIN || pCtx->end.key < pCtx->startTs) {
-        goto interp_exit;
-      }
-
-      COPY_TYPED_DATA(pCtx->pOutput, pCtx->inputType, &pCtx->end.val);
-      break;
-
-    case TSDB_FILL_NONE:
-      // do nothing
-    default:
-      goto interp_exit;
-  }
-
-
-  interp_success_exit:
-  *(TSKEY*)pCtx->ptsOutputBuf = pCtx->startTs;
-  INC_INIT_VAL(pCtx, 1);
-
-  interp_exit:
-  pCtx->start.key = INT64_MIN;
-  pCtx->end.key = INT64_MIN;
-  pCtx->endTs = pCtx->startTs;
-#endif
-
-  return TSDB_CODE_SUCCESS;
-}
-
 int32_t cachedLastRowFunction(SqlFunctionCtx* pCtx) {
   int32_t numOfElems = 0;
 

From 0228caaa0d23944c3ff0eb1f842bbabcd6490257 Mon Sep 17 00:00:00 2001
From: Xiaoyu Wang <xiaoyuwang@taosdata.com>
Date: Tue, 18 Oct 2022 11:38:59 +0800
Subject: [PATCH 07/24] enh: last cache optimize

---
 include/libs/function/functionMgt.h           |  3 +
 source/libs/function/src/builtins.c           | 10 +++
 source/libs/function/src/functionMgt.c        |  6 ++
 source/libs/planner/src/planOptimizer.c       | 78 +++++++++++++++++--
 source/libs/planner/test/planBasicTest.cpp    | 18 -----
 source/libs/planner/test/planOptimizeTest.cpp | 19 +++++
 6 files changed, 109 insertions(+), 25 deletions(-)

diff --git a/include/libs/function/functionMgt.h b/include/libs/function/functionMgt.h
index 569c16675d..6968f1712c 100644
--- a/include/libs/function/functionMgt.h
+++ b/include/libs/function/functionMgt.h
@@ -129,6 +129,7 @@ typedef enum EFunctionType {
   FUNCTION_TYPE_TO_COLUMN,
   FUNCTION_TYPE_GROUP_KEY,
   FUNCTION_TYPE_CACHE_LAST_ROW,
+  FUNCTION_TYPE_CACHE_LAST,
 
   // distributed splitting functions
   FUNCTION_TYPE_APERCENTILE_PARTIAL = 4000,
@@ -216,6 +217,8 @@ bool fmIsKeepOrderFunc(int32_t funcId);
 bool fmIsCumulativeFunc(int32_t funcId);
 bool fmIsInterpPseudoColumnFunc(int32_t funcId);
 
+void getLastCacheDataType(SDataType* pType);
+
 int32_t fmGetDistMethod(const SFunctionNode* pFunc, SFunctionNode** pPartialFunc, SFunctionNode** pMergeFunc);
 
 typedef enum EFuncDataRequired {
diff --git a/source/libs/function/src/builtins.c b/source/libs/function/src/builtins.c
index 54e8c27d5b..f03d8354fa 100644
--- a/source/libs/function/src/builtins.c
+++ b/source/libs/function/src/builtins.c
@@ -2405,6 +2405,16 @@ const SBuiltinFuncDefinition funcMgtBuiltins[] = {
     .processFunc  = lastFunctionMerge,
     .finalizeFunc = firstLastFinalize
   },
+  {
+    .name = "_cache_last",
+    .type = FUNCTION_TYPE_CACHE_LAST,
+    .classification = FUNC_MGT_AGG_FUNC | FUNC_MGT_MULTI_RES_FUNC | FUNC_MGT_FORBID_STREAM_FUNC,
+    .translateFunc = translateFirstLast,
+    .getEnvFunc   = getFirstLastFuncEnv,
+    .initFunc     = functionSetup,
+    .processFunc  = lastFunctionMerge,
+    .finalizeFunc = firstLastFinalize
+  },
   {
     .name = "_last_row_partial",
     .type = FUNCTION_TYPE_LAST_PARTIAL,
diff --git a/source/libs/function/src/functionMgt.c b/source/libs/function/src/functionMgt.c
index ca8ddbc60a..40af7bb567 100644
--- a/source/libs/function/src/functionMgt.c
+++ b/source/libs/function/src/functionMgt.c
@@ -16,6 +16,7 @@
 #include "functionMgt.h"
 
 #include "builtins.h"
+#include "builtinsimpl.h"
 #include "functionMgtInt.h"
 #include "taos.h"
 #include "taoserror.h"
@@ -314,6 +315,11 @@ bool fmIsSameInOutType(int32_t funcId) {
   return res;
 }
 
+void getLastCacheDataType(SDataType* pType) {
+  pType->bytes = getFirstLastInfoSize(pType->bytes) + VARSTR_HEADER_SIZE;
+  pType->type = TSDB_DATA_TYPE_BINARY;
+}
+
 static int32_t getFuncInfo(SFunctionNode* pFunc) {
   char msg[128] = {0};
   return fmGetFuncInfo(pFunc, msg, sizeof(msg));
diff --git a/source/libs/planner/src/planOptimizer.c b/source/libs/planner/src/planOptimizer.c
index 9a2cfa3339..0fc1be8a70 100644
--- a/source/libs/planner/src/planOptimizer.c
+++ b/source/libs/planner/src/planOptimizer.c
@@ -2120,6 +2120,22 @@ static int32_t rewriteUniqueOptimize(SOptimizeContext* pCxt, SLogicSubplan* pLog
   return rewriteUniqueOptimizeImpl(pCxt, pLogicSubplan, pIndef);
 }
 
+static EDealRes lastRowScanOptHasTagImpl(SNode* pNode, void* pContext) {
+  if (QUERY_NODE_COLUMN == nodeType(pNode)) {
+    if (COLUMN_TYPE_TAG == ((SColumnNode*)pNode)->colType || COLUMN_TYPE_TBNAME == ((SColumnNode*)pNode)->colType) {
+      *(bool*)pContext = true;
+      return DEAL_RES_END;
+    }
+  }
+  return DEAL_RES_CONTINUE;
+}
+
+static bool lastRowScanOptHasTag(SNode* pExpr) {
+  bool hasTag = false;
+  nodesWalkExpr(pExpr, lastRowScanOptHasTagImpl, &hasTag);
+  return hasTag;
+}
+
 static bool lastRowScanOptMayBeOptimized(SLogicNode* pNode) {
   if (QUERY_NODE_LOGIC_PLAN_AGG != nodeType(pNode) || 1 != LIST_LENGTH(pNode->pChildren) ||
       QUERY_NODE_LOGIC_PLAN_SCAN != nodeType(nodesListGetNode(pNode->pChildren, 0))) {
@@ -2134,12 +2150,22 @@ static bool lastRowScanOptMayBeOptimized(SLogicNode* pNode) {
     return false;
   }
 
+  bool   hasLastFunc = false;
+  bool   hasSelectFunc = false;
   SNode* pFunc = NULL;
   FOREACH(pFunc, ((SAggLogicNode*)pNode)->pAggFuncs) {
-    if (FUNCTION_TYPE_LAST_ROW != ((SFunctionNode*)pFunc)->funcType &&
-         FUNCTION_TYPE_LAST != ((SFunctionNode*)pFunc)->funcType &&
-        FUNCTION_TYPE_SELECT_VALUE != ((SFunctionNode*)pFunc)->funcType &&
-        FUNCTION_TYPE_GROUP_KEY != ((SFunctionNode*)pFunc)->funcType) {
+    SFunctionNode* pAggFunc = (SFunctionNode*)pFunc;
+    if (FUNCTION_TYPE_LAST == pAggFunc->funcType) {
+      if (hasSelectFunc || lastRowScanOptHasTag(nodesListGetNode(pAggFunc->pParameterList, 0))) {
+        return false;
+      }
+      hasLastFunc = true;
+    } else if (FUNCTION_TYPE_SELECT_VALUE == pAggFunc->funcType || FUNCTION_TYPE_GROUP_KEY == pAggFunc->funcType) {
+      if (hasLastFunc) {
+        return false;
+      }
+      hasSelectFunc = true;
+    } else if (FUNCTION_TYPE_LAST_ROW != pAggFunc->funcType) {
       return false;
     }
   }
@@ -2147,6 +2173,31 @@ static bool lastRowScanOptMayBeOptimized(SLogicNode* pNode) {
   return true;
 }
 
+typedef struct SLastRowScanOptSetColDataTypeCxt {
+  bool       doAgg;
+  SNodeList* pLastCols;
+} SLastRowScanOptSetColDataTypeCxt;
+
+static EDealRes lastRowScanOptSetColDataType(SNode* pNode, void* pContext) {
+  if (QUERY_NODE_COLUMN == nodeType(pNode)) {
+    SLastRowScanOptSetColDataTypeCxt* pCxt = pContext;
+    if (pCxt->doAgg) {
+      nodesListMakeAppend(&pCxt->pLastCols, pNode);
+      getLastCacheDataType(&(((SColumnNode*)pNode)->node.resType));
+    } else {
+      SNode* pCol = NULL;
+      FOREACH(pCol, pCxt->pLastCols) {
+        if (nodesEqualNode(pCol, pNode)) {
+          getLastCacheDataType(&(((SColumnNode*)pNode)->node.resType));
+          break;
+        }
+      }
+    }
+    return DEAL_RES_IGNORE_CHILD;
+  }
+  return DEAL_RES_CONTINUE;
+}
+
 static int32_t lastRowScanOptimize(SOptimizeContext* pCxt, SLogicSubplan* pLogicSubplan) {
   SAggLogicNode* pAgg = (SAggLogicNode*)optFindPossibleNode(pLogicSubplan->pNode, lastRowScanOptMayBeOptimized);
 
@@ -2154,22 +2205,35 @@ static int32_t lastRowScanOptimize(SOptimizeContext* pCxt, SLogicSubplan* pLogic
     return TSDB_CODE_SUCCESS;
   }
 
-  SNode* pNode = NULL;
+  SLastRowScanOptSetColDataTypeCxt cxt = {.doAgg = true, .pLastCols = NULL};
+  SNode*                           pNode = NULL;
   FOREACH(pNode, pAgg->pAggFuncs) {
     SFunctionNode* pFunc = (SFunctionNode*)pNode;
-    if (FUNCTION_TYPE_LAST_ROW == pFunc->funcType || FUNCTION_TYPE_LAST == pFunc->funcType) {
-      int32_t len = snprintf(pFunc->functionName, sizeof(pFunc->functionName), "_cache_last_row");
+    int32_t        funcType = pFunc->funcType;
+    if (FUNCTION_TYPE_LAST_ROW == funcType || FUNCTION_TYPE_LAST == funcType) {
+      int32_t len = snprintf(pFunc->functionName, sizeof(pFunc->functionName),
+                             FUNCTION_TYPE_LAST_ROW == funcType ? "_cache_last_row" : "_cache_last");
       pFunc->functionName[len] = '\0';
       int32_t code = fmGetFuncInfo(pFunc, NULL, 0);
       if (TSDB_CODE_SUCCESS != code) {
+        nodesClearList(cxt.pLastCols);
         return code;
       }
+      if (FUNCTION_TYPE_LAST == funcType) {
+        nodesWalkExpr(nodesListGetNode(pFunc->pParameterList, 0), lastRowScanOptSetColDataType, &cxt);
+      }
     }
   }
 
   SScanLogicNode* pScan = (SScanLogicNode*)nodesListGetNode(pAgg->node.pChildren, 0);
   pScan->scanType = SCAN_TYPE_LAST_ROW;
   pScan->igLastNull = pAgg->hasLast ? true : false;
+  if (NULL != cxt.pLastCols) {
+    cxt.doAgg = false;
+    nodesWalkExprs(pScan->pScanCols, lastRowScanOptSetColDataType, &cxt);
+    nodesWalkExprs(pScan->pScanPseudoCols, lastRowScanOptSetColDataType, &cxt);
+    nodesClearList(cxt.pLastCols);
+  }
   pAgg->hasLastRow = false;
   pAgg->hasLast = false;
 
diff --git a/source/libs/planner/test/planBasicTest.cpp b/source/libs/planner/test/planBasicTest.cpp
index 0baec147a2..c5a9a447c7 100644
--- a/source/libs/planner/test/planBasicTest.cpp
+++ b/source/libs/planner/test/planBasicTest.cpp
@@ -105,24 +105,6 @@ TEST_F(PlanBasicTest, interpFunc) {
   run("SELECT _IROWTS, INTERP(c1) FROM t1 RANGE('2017-7-14 18:00:00', '2017-7-14 19:00:00') EVERY(5s) FILL(LINEAR)");
 }
 
-TEST_F(PlanBasicTest, lastRowFunc) {
-  useDb("root", "cache_db");
-
-  run("SELECT LAST_ROW(c1) FROM t1");
-
-  run("SELECT LAST_ROW(*) FROM t1");
-
-  run("SELECT LAST_ROW(c1, c2) FROM t1");
-
-  run("SELECT LAST_ROW(c1), c2 FROM t1");
-
-  run("SELECT LAST_ROW(c1) FROM st1");
-
-  run("SELECT LAST_ROW(c1) FROM st1 PARTITION BY TBNAME");
-
-  run("SELECT LAST_ROW(c1), SUM(c3) FROM t1");
-}
-
 TEST_F(PlanBasicTest, lastRowFuncWithoutCache) {
   useDb("root", "test");
 
diff --git a/source/libs/planner/test/planOptimizeTest.cpp b/source/libs/planner/test/planOptimizeTest.cpp
index c2a0aee847..fb4f32a9bf 100644
--- a/source/libs/planner/test/planOptimizeTest.cpp
+++ b/source/libs/planner/test/planOptimizeTest.cpp
@@ -109,9 +109,28 @@ TEST_F(PlanOptimizeTest, mergeProjects) {
 
 TEST_F(PlanOptimizeTest, pushDownProjectCond) {
   useDb("root", "test");
+
   run("select 1-abs(c1) from (select unique(c1) c1 from st1s3) where 1-c1>5 order by 1 nulls first");
 }
 
+TEST_F(PlanOptimizeTest, LastRowScan) {
+  useDb("root", "cache_db");
+
+  run("SELECT LAST_ROW(c1), c2 FROM t1");
+
+  run("SELECT LAST_ROW(c1), c2, tag1, tbname FROM st1");
+
+  run("SELECT LAST_ROW(c1) FROM st1 PARTITION BY TBNAME");
+
+  run("SELECT LAST_ROW(c1), SUM(c3) FROM t1");
+
+  run("SELECT LAST_ROW(tag1) FROM st1");
+
+  run("SELECT LAST(c1) FROM st1");
+
+  run("SELECT LAST(c1), c2 FROM st1");
+}
+
 TEST_F(PlanOptimizeTest, tagScan) {
   useDb("root", "test");
   run("select tag1 from st1 group by tag1");

From 60e7f2800bc350f53333efd0c341bab0febf5dc7 Mon Sep 17 00:00:00 2001
From: Haojun Liao <hjliao@taosdata.com>
Date: Tue, 18 Oct 2022 17:39:28 +0800
Subject: [PATCH 08/24] fix(query): fix bug in cached last query.

---
 source/dnode/vnode/src/tsdb/tsdbCacheRead.c | 151 ++++++++++++--------
 source/libs/planner/src/planOptimizer.c     |   1 +
 2 files changed, 95 insertions(+), 57 deletions(-)

diff --git a/source/dnode/vnode/src/tsdb/tsdbCacheRead.c b/source/dnode/vnode/src/tsdb/tsdbCacheRead.c
index be36848fec..791c73047c 100644
--- a/source/dnode/vnode/src/tsdb/tsdbCacheRead.c
+++ b/source/dnode/vnode/src/tsdb/tsdbCacheRead.c
@@ -30,36 +30,69 @@ typedef struct SCacheRowsReader {
 } SCacheRowsReader;
 
 static void saveOneRow(SArray* pRow, SSDataBlock* pBlock, SCacheRowsReader* pReader, const int32_t* slotIds,
-                       SFirstLastRes** pRes) {
+                       void** pRes) {
   ASSERT(pReader->numOfCols <= taosArrayGetSize(pBlock->pDataBlock));
   int32_t numOfRows = pBlock->info.rows;
 
-  for (int32_t i = 0; i < pReader->numOfCols; ++i) {
-    SColumnInfoData* pColInfoData = taosArrayGet(pBlock->pDataBlock, i);
+  if ((pReader->type & CACHESCAN_RETRIEVE_LAST) == CACHESCAN_RETRIEVE_LAST) {
+    for (int32_t i = 0; i < pReader->numOfCols; ++i) {
+      SColumnInfoData* pColInfoData = taosArrayGet(pBlock->pDataBlock, i);
+      SFirstLastRes*   p = (SFirstLastRes*)varDataVal(pRes[i]);
 
-    if (slotIds[i] == -1) {  // the primary timestamp
-      SLastCol* pColVal = (SLastCol*)taosArrayGet(pRow, 0);
-      pRes[i]->ts = pColVal->ts;
-      memcpy(pRes[i]->buf, &pColVal->ts, TSDB_KEYSIZE);
-    } else {
-      int32_t   slotId = slotIds[i];
-      SLastCol* pColVal = (SLastCol*)taosArrayGet(pRow, slotId);
+      if (slotIds[i] == -1) {  // the primary timestamp
+        SLastCol* pColVal = (SLastCol*)taosArrayGet(pRow, 0);
+        p->ts = pColVal->ts;
+        p->bytes = TSDB_KEYSIZE;
+        *(int64_t*)p->buf = pColVal->ts;
+      } else {
+        int32_t   slotId = slotIds[i];
+        SLastCol* pColVal = (SLastCol*)taosArrayGet(pRow, slotId);
 
-      pRes[i]->ts = pColVal->ts;
-      pRes[i]->isNull = !COL_VAL_IS_VALUE(&pColVal->colVal);
+        p->ts = pColVal->ts;
+        p->isNull = !COL_VAL_IS_VALUE(&pColVal->colVal);
+        if (!p->isNull) {
+          if (IS_VAR_DATA_TYPE(pColVal->colVal.type)) {
+            varDataSetLen(p->buf, pColVal->colVal.value.nData);
+            memcpy(varDataVal(p->buf), pColVal->colVal.value.pData, pColVal->colVal.value.nData);
+            p->bytes = pColVal->colVal.value.nData;
+          } else {
+            memcpy(p->buf, &pColVal->colVal.value, pReader->pSchema->columns[slotId].bytes);
+            p->bytes = pReader->pSchema->columns[slotId].bytes;
+          }
+        }
+      }
 
-      if (!pRes[i]->isNull) {
-        if (IS_VAR_DATA_TYPE(pColVal->colVal.type)) {
-          varDataSetLen(pRes[i]->buf, pColVal->colVal.value.nData);
-          memcpy(varDataVal(pRes[i]->buf), pColVal->colVal.value.pData, pColVal->colVal.value.nData);
+      p->hasResult = true;
+      varDataSetLen(pRes[i], pColInfoData->info.bytes);
+      colDataAppend(pColInfoData, numOfRows, (const char*)pRes[i], false);
+    }
+  } else {
+    ASSERT((pReader->type & CACHESCAN_RETRIEVE_LAST_ROW) == CACHESCAN_RETRIEVE_LAST_ROW);
+
+    SColVal colVal = {0};
+    for (int32_t i = 0; i < pReader->numOfCols; ++i) {
+      SColumnInfoData* pColInfoData = taosArrayGet(pBlock->pDataBlock, i);
+
+      if (slotIds[i] == -1) {
+        SLastCol* pColVal = (SLastCol*)taosArrayGet(pRow, 0);
+        colDataAppend(pColInfoData, numOfRows, (const char*)&pColVal->ts, false);
+      } else {
+        int32_t   slotId = slotIds[i];
+        SLastCol* pColVal = (SLastCol*)taosArrayGet(pRow, slotId);
+
+        if (IS_VAR_DATA_TYPE(colVal.type)) {
+          if (!COL_VAL_IS_VALUE(&pColVal->colVal)) {
+            colDataAppendNULL(pColInfoData, numOfRows);
+          } else {
+            varDataSetLen(pReader->transferBuf[slotId], colVal.value.nData);
+            memcpy(varDataVal(pReader->transferBuf[slotId]), colVal.value.pData, colVal.value.nData);
+            colDataAppend(pColInfoData, numOfRows, pReader->transferBuf[slotId], false);
+          }
         } else {
-          memcpy(pRes[i]->buf, &pColVal->colVal.value, pReader->pSchema->columns[slotId].bytes);
+          colDataAppend(pColInfoData, numOfRows, (const char*)&colVal.value, !COL_VAL_IS_VALUE(&pColVal->colVal));
         }
       }
     }
-
-    pRes[i]->hasResult = true;
-    colDataAppend(pColInfoData, numOfRows, (const char*)pRes[i], false);
   }
 
   pBlock->info.rows += 1;
@@ -126,24 +159,17 @@ static int32_t doExtractCacheRow(SCacheRowsReader* pr, SLRUCache* lruCache, uint
   int32_t code = TSDB_CODE_SUCCESS;
   if ((pr->type & CACHESCAN_RETRIEVE_LAST_ROW) == CACHESCAN_RETRIEVE_LAST_ROW) {
     code = tsdbCacheGetLastrowH(lruCache, uid, pr->pVnode->pTsdb, h);
-    if (code != TSDB_CODE_SUCCESS) {
-      return code;
-    }
-
-    // no data in the table of Uid
-    if (*h != NULL) {
-      *pRow = (SArray*)taosLRUCacheValue(lruCache, *h);
-    }
   } else {
     code = tsdbCacheGetLastH(lruCache, uid, pr->pVnode->pTsdb, h);
-    if (code != TSDB_CODE_SUCCESS) {
-      return code;
-    }
+  }
 
-    // no data in the table of Uid
-    if (*h != NULL) {
-      *pRow = (SArray*)taosLRUCacheValue(lruCache, *h);
-    }
+  if (code != TSDB_CODE_SUCCESS) {
+    return code;
+  }
+
+  // no data in the table of Uid
+  if (*h != NULL) {
+    *pRow = (SArray*)taosLRUCacheValue(lruCache, *h);
   }
 
   return code;
@@ -163,10 +189,26 @@ int32_t tsdbRetrieveCacheRows(void* pReader, SSDataBlock* pResBlock, const int32
   size_t     numOfTables = taosArrayGetSize(pr->pTableList);
   bool       hasRes = false;
 
-  SFirstLastRes** pRes = taosMemoryCalloc(pr->numOfCols, POINTER_BYTES);
+  void** pRes = taosMemoryCalloc(pr->numOfCols, POINTER_BYTES);
   for (int32_t j = 0; j < pr->numOfCols; ++j) {
-    pRes[j] = taosMemoryCalloc(1, sizeof(SFirstLastRes) + pr->pSchema->columns[slotIds[j]].bytes);
-    pRes[j]->ts = INT64_MIN;
+    pRes[j] = taosMemoryCalloc(1, sizeof(SFirstLastRes) + pr->pSchema->columns[slotIds[j]].bytes + VARSTR_HEADER_SIZE);
+    SFirstLastRes* p = (SFirstLastRes*)varDataVal(pRes[j]);
+    p->ts = INT64_MIN;
+  }
+
+  SArray* pLastCols = taosArrayInit(pr->pSchema->numOfCols, sizeof(SLastCol));
+  for (int32_t i = 0; i < pr->numOfCols; ++i) {
+    SLastCol p = {0};
+    p.ts = INT64_MIN;
+
+    struct STColumn* pCol = &pr->pSchema->columns[i];
+    p.colVal.type = pCol->type;
+
+    if (IS_VAR_DATA_TYPE(pCol->type)) {
+      p.colVal.value.pData = taosMemoryCalloc(pCol->bytes, sizeof(char));
+    }
+
+    taosArrayPush(pLastCols, &p);
   }
 
   // retrieve the only one last row of all tables in the uid list.
@@ -185,38 +227,32 @@ int32_t tsdbRetrieveCacheRows(void* pReader, SSDataBlock* pResBlock, const int32
 
       {
         for (int32_t k = 0; k < pr->numOfCols; ++k) {
-          SColumnInfoData* pColInfoData = taosArrayGet(pResBlock->pDataBlock, k);
-
+          SLastCol* p = taosArrayGet(pLastCols, k);
           if (slotIds[k] == -1) {  // the primary timestamp
-            SLastCol* pColVal = (SLastCol*)taosArrayGet(pRow, k);
-            if (pColVal->ts > pRes[k]->ts || !pRes[k]->hasResult) {
+            SLastCol* pCol = (SLastCol*)taosArrayGet(pRow, k);
+            if (pCol->ts > p->ts) {
               hasRes = true;
-              pRes[k]->hasResult = true;
-              pRes[k]->ts = pColVal->ts;
-              memcpy(pRes[k]->buf, &pColVal->ts, TSDB_KEYSIZE);
-
-              colDataAppend(pColInfoData, 1, (const char*)pRes[k], false);
+              p->ts = pCol->ts;
+              p->colVal = pCol->colVal;
             }
           } else {
             int32_t   slotId = slotIds[k];
             SLastCol* pColVal = (SLastCol*)taosArrayGet(pRow, slotId);
 
-            if (pColVal->ts > pRes[k]->ts || !pRes[k]->hasResult) {
+            if (pColVal->ts > p->ts) {
               hasRes = true;
-              pRes[k]->hasResult = true;
-              pRes[k]->ts = pColVal->ts;
+              p->ts = pColVal->ts;
 
-              pRes[k]->isNull = !COL_VAL_IS_VALUE(&pColVal->colVal);
-              if (!pRes[k]->isNull) {
+              if (!COL_VAL_IS_VALUE(&pColVal->colVal)) {
                 if (IS_VAR_DATA_TYPE(pColVal->colVal.type)) {
-                  varDataSetLen(pRes[k]->buf, pColVal->colVal.value.nData);
-                  memcpy(varDataVal(pRes[k]->buf), pColVal->colVal.value.pData, pColVal->colVal.value.nData);
+                  uint8_t* px = p->colVal.value.pData;
+                  p->colVal = pColVal->colVal;
+                  p->colVal.value.pData = px;
+                  memcpy(px, pColVal->colVal.value.pData, pColVal->colVal.value.nData);
                 } else {
-                  memcpy(pRes[k]->buf, &pColVal->colVal.value, pr->pSchema->columns[slotId].bytes);
+                  p->colVal = pColVal->colVal;
                 }
               }
-
-              colDataAppend(pColInfoData, 1, (const char*)pRes[k], false);
             }
           }
         }
@@ -227,6 +263,7 @@ int32_t tsdbRetrieveCacheRows(void* pReader, SSDataBlock* pResBlock, const int32
 
     if (hasRes) {
       pResBlock->info.rows = 1;
+      saveOneRow(pLastCols, pResBlock, pr, slotIds, pRes);
     }
 
   } else if ((pr->type & CACHESCAN_RETRIEVE_TYPE_ALL) == CACHESCAN_RETRIEVE_TYPE_ALL) {
diff --git a/source/libs/planner/src/planOptimizer.c b/source/libs/planner/src/planOptimizer.c
index 0fc1be8a70..7a145e7dde 100644
--- a/source/libs/planner/src/planOptimizer.c
+++ b/source/libs/planner/src/planOptimizer.c
@@ -2232,6 +2232,7 @@ static int32_t lastRowScanOptimize(SOptimizeContext* pCxt, SLogicSubplan* pLogic
     cxt.doAgg = false;
     nodesWalkExprs(pScan->pScanCols, lastRowScanOptSetColDataType, &cxt);
     nodesWalkExprs(pScan->pScanPseudoCols, lastRowScanOptSetColDataType, &cxt);
+    nodesWalkExprs(pScan->node.pTargets, lastRowScanOptSetColDataType, &cxt);
     nodesClearList(cxt.pLastCols);
   }
   pAgg->hasLastRow = false;

From e4940e82c53ac6d616077768438fe15189705d6d Mon Sep 17 00:00:00 2001
From: Haojun Liao <hjliao@taosdata.com>
Date: Tue, 18 Oct 2022 17:54:29 +0800
Subject: [PATCH 09/24] fix(query): update last_row  callback function.

---
 source/libs/function/src/builtins.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/source/libs/function/src/builtins.c b/source/libs/function/src/builtins.c
index f03d8354fa..4644b15dea 100644
--- a/source/libs/function/src/builtins.c
+++ b/source/libs/function/src/builtins.c
@@ -2402,7 +2402,7 @@ const SBuiltinFuncDefinition funcMgtBuiltins[] = {
     .translateFunc = translateFirstLast,
     .getEnvFunc   = getFirstLastFuncEnv,
     .initFunc     = functionSetup,
-    .processFunc  = lastFunctionMerge,
+    .processFunc  = lastRowFunction,
     .finalizeFunc = firstLastFinalize
   },
   {

From d7e01b30c7ba5e67bc71b1387d11376347daecba Mon Sep 17 00:00:00 2001
From: Haojun Liao <hjliao@taosdata.com>
Date: Tue, 18 Oct 2022 19:13:42 +0800
Subject: [PATCH 10/24] fix(query): update last_row  callback function.

---
 source/dnode/vnode/src/tsdb/tsdbCacheRead.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/source/dnode/vnode/src/tsdb/tsdbCacheRead.c b/source/dnode/vnode/src/tsdb/tsdbCacheRead.c
index 791c73047c..38c10e8354 100644
--- a/source/dnode/vnode/src/tsdb/tsdbCacheRead.c
+++ b/source/dnode/vnode/src/tsdb/tsdbCacheRead.c
@@ -54,7 +54,7 @@ static void saveOneRow(SArray* pRow, SSDataBlock* pBlock, SCacheRowsReader* pRea
           if (IS_VAR_DATA_TYPE(pColVal->colVal.type)) {
             varDataSetLen(p->buf, pColVal->colVal.value.nData);
             memcpy(varDataVal(p->buf), pColVal->colVal.value.pData, pColVal->colVal.value.nData);
-            p->bytes = pColVal->colVal.value.nData;
+            p->bytes = pColVal->colVal.value.nData + VARSTR_HEADER_SIZE;
           } else {
             memcpy(p->buf, &pColVal->colVal.value, pReader->pSchema->columns[slotId].bytes);
             p->bytes = pReader->pSchema->columns[slotId].bytes;

From c7c99ae34634be4ec6852bdc6f6961c132264c8b Mon Sep 17 00:00:00 2001
From: Haojun Liao <hjliao@taosdata.com>
Date: Wed, 19 Oct 2022 09:33:54 +0800
Subject: [PATCH 11/24] fix(query): update last_row  callback function.

---
 source/dnode/vnode/src/tsdb/tsdbCacheRead.c | 27 +++++++++++++++++----
 source/libs/function/src/builtins.c         |  2 +-
 2 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/source/dnode/vnode/src/tsdb/tsdbCacheRead.c b/source/dnode/vnode/src/tsdb/tsdbCacheRead.c
index 38c10e8354..63c889985a 100644
--- a/source/dnode/vnode/src/tsdb/tsdbCacheRead.c
+++ b/source/dnode/vnode/src/tsdb/tsdbCacheRead.c
@@ -188,15 +188,26 @@ int32_t tsdbRetrieveCacheRows(void* pReader, SSDataBlock* pResBlock, const int32
   SArray*    pRow = NULL;
   size_t     numOfTables = taosArrayGetSize(pr->pTableList);
   bool       hasRes = false;
+  SArray*    pLastCols = NULL;
 
   void** pRes = taosMemoryCalloc(pr->numOfCols, POINTER_BYTES);
+  if (pRes == NULL) {
+    code = TSDB_CODE_OUT_OF_MEMORY;
+    goto _end;
+  }
+
   for (int32_t j = 0; j < pr->numOfCols; ++j) {
     pRes[j] = taosMemoryCalloc(1, sizeof(SFirstLastRes) + pr->pSchema->columns[slotIds[j]].bytes + VARSTR_HEADER_SIZE);
     SFirstLastRes* p = (SFirstLastRes*)varDataVal(pRes[j]);
     p->ts = INT64_MIN;
   }
 
-  SArray* pLastCols = taosArrayInit(pr->pSchema->numOfCols, sizeof(SLastCol));
+  pLastCols = taosArrayInit(pr->pSchema->numOfCols, sizeof(SLastCol));
+  if (pLastCols == NULL) {
+    code = TSDB_CODE_OUT_OF_MEMORY;
+    goto _end;
+  }
+
   for (int32_t i = 0; i < pr->numOfCols; ++i) {
     SLastCol p = {0};
     p.ts = INT64_MIN;
@@ -262,7 +273,6 @@ int32_t tsdbRetrieveCacheRows(void* pReader, SSDataBlock* pResBlock, const int32
     }
 
     if (hasRes) {
-      pResBlock->info.rows = 1;
       saveOneRow(pLastCols, pResBlock, pr, slotIds, pRes);
     }
 
@@ -286,12 +296,19 @@ int32_t tsdbRetrieveCacheRows(void* pReader, SSDataBlock* pResBlock, const int32
 
       pr->tableIndex += 1;
       if (pResBlock->info.rows >= pResBlock->info.capacity) {
-        return TSDB_CODE_SUCCESS;
+        goto _end;
       }
     }
   } else {
-    return TSDB_CODE_INVALID_PARA;
+    code = TSDB_CODE_INVALID_PARA;
   }
 
-  return TSDB_CODE_SUCCESS;
+  _end:
+  for (int32_t j = 0; j < pr->numOfCols; ++j) {
+    taosMemoryFree(pRes[j]);
+  }
+
+  taosMemoryFree(pRes);
+  taosArrayDestroy(pLastCols);
+  return code;
 }
diff --git a/source/libs/function/src/builtins.c b/source/libs/function/src/builtins.c
index 4644b15dea..ce440a525a 100644
--- a/source/libs/function/src/builtins.c
+++ b/source/libs/function/src/builtins.c
@@ -2402,7 +2402,7 @@ const SBuiltinFuncDefinition funcMgtBuiltins[] = {
     .translateFunc = translateFirstLast,
     .getEnvFunc   = getFirstLastFuncEnv,
     .initFunc     = functionSetup,
-    .processFunc  = lastRowFunction,
+    .processFunc  = cachedLastRowFunction,
     .finalizeFunc = firstLastFinalize
   },
   {

From 5dcd319d3b566b16e25ae4ee83c982de133a9a79 Mon Sep 17 00:00:00 2001
From: Haojun Liao <hjliao@taosdata.com>
Date: Wed, 19 Oct 2022 10:07:20 +0800
Subject: [PATCH 12/24] fix(query): update last_row  callback function.

---
 source/dnode/vnode/src/tsdb/tsdbCacheRead.c | 21 ++++++++++-----------
 1 file changed, 10 insertions(+), 11 deletions(-)

diff --git a/source/dnode/vnode/src/tsdb/tsdbCacheRead.c b/source/dnode/vnode/src/tsdb/tsdbCacheRead.c
index 63c889985a..53f8d5be16 100644
--- a/source/dnode/vnode/src/tsdb/tsdbCacheRead.c
+++ b/source/dnode/vnode/src/tsdb/tsdbCacheRead.c
@@ -69,7 +69,6 @@ static void saveOneRow(SArray* pRow, SSDataBlock* pBlock, SCacheRowsReader* pRea
   } else {
     ASSERT((pReader->type & CACHESCAN_RETRIEVE_LAST_ROW) == CACHESCAN_RETRIEVE_LAST_ROW);
 
-    SColVal colVal = {0};
     for (int32_t i = 0; i < pReader->numOfCols; ++i) {
       SColumnInfoData* pColInfoData = taosArrayGet(pBlock->pDataBlock, i);
 
@@ -79,17 +78,18 @@ static void saveOneRow(SArray* pRow, SSDataBlock* pBlock, SCacheRowsReader* pRea
       } else {
         int32_t   slotId = slotIds[i];
         SLastCol* pColVal = (SLastCol*)taosArrayGet(pRow, slotId);
+        SColVal*  pVal = &pColVal->colVal;
 
-        if (IS_VAR_DATA_TYPE(colVal.type)) {
+        if (IS_VAR_DATA_TYPE(pColVal->colVal.type)) {
           if (!COL_VAL_IS_VALUE(&pColVal->colVal)) {
             colDataAppendNULL(pColInfoData, numOfRows);
           } else {
-            varDataSetLen(pReader->transferBuf[slotId], colVal.value.nData);
-            memcpy(varDataVal(pReader->transferBuf[slotId]), colVal.value.pData, colVal.value.nData);
+            varDataSetLen(pReader->transferBuf[slotId], pVal->value.nData);
+            memcpy(varDataVal(pReader->transferBuf[slotId]), pVal->value.pData, pVal->value.nData);
             colDataAppend(pColInfoData, numOfRows, pReader->transferBuf[slotId], false);
           }
         } else {
-          colDataAppend(pColInfoData, numOfRows, (const char*)&colVal.value, !COL_VAL_IS_VALUE(&pColVal->colVal));
+          colDataAppend(pColInfoData, numOfRows, (const char*)&pVal->value.val, !COL_VAL_IS_VALUE(pVal));
         }
       }
     }
@@ -157,6 +157,8 @@ void* tsdbCacherowsReaderClose(void* pReader) {
 static int32_t doExtractCacheRow(SCacheRowsReader* pr, SLRUCache* lruCache, uint64_t uid, SArray** pRow,
                                  LRUHandle** h) {
   int32_t code = TSDB_CODE_SUCCESS;
+  *pRow = NULL;
+
   if ((pr->type & CACHESCAN_RETRIEVE_LAST_ROW) == CACHESCAN_RETRIEVE_LAST_ROW) {
     code = tsdbCacheGetLastrowH(lruCache, uid, pr->pVnode->pTsdb, h);
   } else {
@@ -208,12 +210,9 @@ int32_t tsdbRetrieveCacheRows(void* pReader, SSDataBlock* pResBlock, const int32
     goto _end;
   }
 
-  for (int32_t i = 0; i < pr->numOfCols; ++i) {
-    SLastCol p = {0};
-    p.ts = INT64_MIN;
-
+  for (int32_t i = 0; i < pr->pSchema->numOfCols; ++i) {
     struct STColumn* pCol = &pr->pSchema->columns[i];
-    p.colVal.type = pCol->type;
+    SLastCol p = {.ts = INT64_MIN, .colVal.type = pCol->type};
 
     if (IS_VAR_DATA_TYPE(pCol->type)) {
       p.colVal.value.pData = taosMemoryCalloc(pCol->bytes, sizeof(char));
@@ -254,7 +253,7 @@ int32_t tsdbRetrieveCacheRows(void* pReader, SSDataBlock* pResBlock, const int32
               hasRes = true;
               p->ts = pColVal->ts;
 
-              if (!COL_VAL_IS_VALUE(&pColVal->colVal)) {
+              if (COL_VAL_IS_VALUE(&pColVal->colVal)) {
                 if (IS_VAR_DATA_TYPE(pColVal->colVal.type)) {
                   uint8_t* px = p->colVal.value.pData;
                   p->colVal = pColVal->colVal;

From 467c6386edd71c116e99acec2091650bff9e4972 Mon Sep 17 00:00:00 2001
From: Minglei Jin <mljin@taosdata.com>
Date: Wed, 19 Oct 2022 11:06:08 +0800
Subject: [PATCH 13/24] fix: last_row array element type

---
 source/dnode/vnode/src/tsdb/tsdbCache.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/source/dnode/vnode/src/tsdb/tsdbCache.c b/source/dnode/vnode/src/tsdb/tsdbCache.c
index f67a5cc444..7f664f9e37 100644
--- a/source/dnode/vnode/src/tsdb/tsdbCache.c
+++ b/source/dnode/vnode/src/tsdb/tsdbCache.c
@@ -1109,7 +1109,7 @@ static int32_t mergeLastRow(tb_uid_t uid, STsdb *pTsdb, bool *dup, SArray **ppCo
   int16_t   iCol = 0;
   int16_t   noneCol = 0;
   bool      setNoneCol = false;
-  SArray   *pColArray = taosArrayInit(nCol, sizeof(SColVal));
+  SArray   *pColArray = taosArrayInit(nCol, sizeof(SLastCol));
   SColVal  *pColVal = &(SColVal){0};
 
   TSKEY lastRowTs = TSKEY_MAX;
@@ -1140,7 +1140,14 @@ static int32_t mergeLastRow(tb_uid_t uid, STsdb *pTsdb, bool *dup, SArray **ppCo
       for (iCol = 1; iCol < nCol; ++iCol) {
         tsdbRowGetColVal(pRow, pTSchema, iCol, pColVal);
 
-        if (taosArrayPush(pColArray, &(SLastCol){.ts = lastRowTs, .colVal = *pColVal}) == NULL) {
+        SLastCol lastCol = {.ts = lastRowTs, .colVal = *pColVal};
+        /*
+        if (IS_VAR_DATA_TYPE(pColVal->type)) {
+          lastCol.colVal.value.pData = taosMemoryMalloc(lastCol.colVal.value.nData);
+          memcpy(lastCol.colVal.value.pData, pColVal->value.pData, pColVal->value.nData);
+        }
+        */
+        if (taosArrayPush(pColArray, &lastCol) == NULL) {
           code = TSDB_CODE_OUT_OF_MEMORY;
           goto _err;
         }

From 12fd11c481b21dbb48194c53609674d25c8341cd Mon Sep 17 00:00:00 2001
From: Haojun Liao <hjliao@taosdata.com>
Date: Wed, 19 Oct 2022 11:41:30 +0800
Subject: [PATCH 14/24] fix(query): fix syntax error.

---
 source/libs/executor/src/timewindowoperator.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/source/libs/executor/src/timewindowoperator.c b/source/libs/executor/src/timewindowoperator.c
index db9ebf12c2..1bcf274460 100644
--- a/source/libs/executor/src/timewindowoperator.c
+++ b/source/libs/executor/src/timewindowoperator.c
@@ -5462,9 +5462,11 @@ SOperatorInfo* createStreamIntervalOperatorInfo(SOperatorInfo* downstream, SPhys
   }
   SStreamIntervalPhysiNode* pIntervalPhyNode = (SStreamIntervalPhysiNode*)pPhyNode;
 
+  int32_t    code = TSDB_CODE_SUCCESS;
   int32_t    numOfCols = 0;
   SExprInfo* pExprInfo = createExprInfo(pIntervalPhyNode->window.pFuncs, NULL, &numOfCols);
   ASSERT(numOfCols > 0);
+
   SSDataBlock* pResBlock = createResDataBlock(pPhyNode->pOutputDataBlockDesc);
   SInterval    interval = {
          .interval = pIntervalPhyNode->interval,
@@ -5474,6 +5476,7 @@ SOperatorInfo* createStreamIntervalOperatorInfo(SOperatorInfo* downstream, SPhys
          .offset = pIntervalPhyNode->offset,
          .precision = ((SColumnNode*)pIntervalPhyNode->window.pTspk)->node.resType.precision,
   };
+
   STimeWindowAggSupp twAggSupp = {
       .waterMark = pIntervalPhyNode->window.watermark,
       .calTrigger = pIntervalPhyNode->window.triggerType,
@@ -5481,6 +5484,7 @@ SOperatorInfo* createStreamIntervalOperatorInfo(SOperatorInfo* downstream, SPhys
       .minTs = INT64_MAX,
       .deleteMark = INT64_MAX,
   };
+
   ASSERT(twAggSupp.calTrigger != STREAM_TRIGGER_MAX_DELAY);
   pOperator->pTaskInfo = pTaskInfo;
   pInfo->interval = interval;
@@ -5502,7 +5506,7 @@ SOperatorInfo* createStreamIntervalOperatorInfo(SOperatorInfo* downstream, SPhys
   }
 
   size_t  keyBufSize = sizeof(int64_t) + sizeof(int64_t) + POINTER_BYTES;
-  int32_t code = initAggInfo(pSup, &pInfo->aggSup, pExprInfo, numOfCols, keyBufSize, pTaskInfo->id.str);
+  code = initAggInfo(pSup, &pInfo->aggSup, pExprInfo, numOfCols, keyBufSize, pTaskInfo->id.str);
   if (code != TSDB_CODE_SUCCESS) {
     goto _error;
   }

From a1c18bba33dc550dc5f6690cc4cf7f4212023482 Mon Sep 17 00:00:00 2001
From: Minglei Jin <mljin@taosdata.com>
Date: Wed, 19 Oct 2022 13:58:59 +0800
Subject: [PATCH 15/24] fix: cache load calculation

---
 source/dnode/vnode/src/tsdb/tsdbCache.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/source/dnode/vnode/src/tsdb/tsdbCache.c b/source/dnode/vnode/src/tsdb/tsdbCache.c
index 7f664f9e37..d3051f78c7 100644
--- a/source/dnode/vnode/src/tsdb/tsdbCache.c
+++ b/source/dnode/vnode/src/tsdb/tsdbCache.c
@@ -1328,9 +1328,9 @@ int32_t tsdbCacheGetLastrowH(SLRUCache *pCache, tb_uid_t uid, STsdb *pTsdb, LRUH
         return 0;
       }
 
+      size_t              charge = pArray->capacity * pArray->elemSize + sizeof(*pArray);
       _taos_lru_deleter_t deleter = deleteTableCacheLast;
-      LRUStatus           status =
-          taosLRUCacheInsert(pCache, key, keyLen, pArray, pArray->capacity, deleter, NULL, TAOS_LRU_PRIORITY_LOW);
+      LRUStatus status = taosLRUCacheInsert(pCache, key, keyLen, pArray, charge, deleter, NULL, TAOS_LRU_PRIORITY_LOW);
       if (status != TAOS_LRU_STATUS_OK) {
         code = -1;
       }
@@ -1395,9 +1395,10 @@ int32_t tsdbCacheGetLastH(SLRUCache *pCache, tb_uid_t uid, STsdb *pTsdb, LRUHand
         return 0;
       }
 
+      size_t              charge = pLastArray->capacity * pLastArray->elemSize + sizeof(*pLastArray);
       _taos_lru_deleter_t deleter = deleteTableCacheLast;
-      LRUStatus status = taosLRUCacheInsert(pCache, key, keyLen, pLastArray, pLastArray->capacity, deleter, NULL,
-                                            TAOS_LRU_PRIORITY_LOW);
+      LRUStatus           status =
+          taosLRUCacheInsert(pCache, key, keyLen, pLastArray, charge, deleter, NULL, TAOS_LRU_PRIORITY_LOW);
       if (status != TAOS_LRU_STATUS_OK) {
         code = -1;
       }

From ceec953498ad481a885c835644921c47c785e625 Mon Sep 17 00:00:00 2001
From: Minglei Jin <mljin@taosdata.com>
Date: Wed, 19 Oct 2022 14:50:36 +0800
Subject: [PATCH 16/24] fix: copy binary type column data out

---
 source/dnode/vnode/src/tsdb/tsdbCache.c | 46 +++++++++++++++++++++----
 1 file changed, 40 insertions(+), 6 deletions(-)

diff --git a/source/dnode/vnode/src/tsdb/tsdbCache.c b/source/dnode/vnode/src/tsdb/tsdbCache.c
index d3051f78c7..d4cca40b89 100644
--- a/source/dnode/vnode/src/tsdb/tsdbCache.c
+++ b/source/dnode/vnode/src/tsdb/tsdbCache.c
@@ -56,7 +56,18 @@ static void getTableCacheKey(tb_uid_t uid, int cacheType, char *key, int *len) {
   *len = sizeof(uint64_t);
 }
 
-static void deleteTableCacheLast(const void *key, size_t keyLen, void *value) { taosArrayDestroy(value); }
+static void deleteTableCacheLast(const void *key, size_t keyLen, void *value) {
+  SArray *pLastArray = (SArray *)value;
+  int16_t nCol = taosArrayGetSize(pLastArray);
+  for (int16_t iCol = 0; iCol < nCol; ++iCol) {
+    SLastCol *pLastCol = (SLastCol *)taosArrayGet(pLastArray, iCol);
+    if (IS_VAR_DATA_TYPE(pLastCol->colVal.type)) {
+      taosMemoryFree(pLastCol->colVal.value.pData);
+    }
+  }
+
+  taosArrayDestroy(value);
+}
 
 int32_t tsdbCacheDeleteLastrow(SLRUCache *pCache, tb_uid_t uid, TSKEY eKey) {
   int32_t code = 0;
@@ -1141,12 +1152,11 @@ static int32_t mergeLastRow(tb_uid_t uid, STsdb *pTsdb, bool *dup, SArray **ppCo
         tsdbRowGetColVal(pRow, pTSchema, iCol, pColVal);
 
         SLastCol lastCol = {.ts = lastRowTs, .colVal = *pColVal};
-        /*
         if (IS_VAR_DATA_TYPE(pColVal->type)) {
           lastCol.colVal.value.pData = taosMemoryMalloc(lastCol.colVal.value.nData);
           memcpy(lastCol.colVal.value.pData, pColVal->value.pData, pColVal->value.nData);
         }
-        */
+
         if (taosArrayPush(pColArray, &lastCol) == NULL) {
           code = TSDB_CODE_OUT_OF_MEMORY;
           goto _err;
@@ -1178,7 +1188,16 @@ static int32_t mergeLastRow(tb_uid_t uid, STsdb *pTsdb, bool *dup, SArray **ppCo
 
       tsdbRowGetColVal(pRow, pTSchema, iCol, pColVal);
       if (COL_VAL_IS_NONE(tColVal) && !COL_VAL_IS_NONE(pColVal)) {
-        taosArraySet(pColArray, iCol, &(SLastCol){.ts = rowTs, .colVal = *pColVal});
+        SLastCol lastCol = {.ts = rowTs, .colVal = *pColVal};
+        if (IS_VAR_DATA_TYPE(pColVal->type)) {
+          SLastCol *pLastCol = (SLastCol *)taosArrayGet(pColArray, iCol);
+          taosMemoryFree(pLastCol->colVal.value.pData);
+
+          lastCol.colVal.value.pData = taosMemoryMalloc(lastCol.colVal.value.nData);
+          memcpy(lastCol.colVal.value.pData, pColVal->value.pData, pColVal->value.nData);
+        }
+
+        taosArraySet(pColArray, iCol, &lastCol);
       } else if (COL_VAL_IS_NONE(tColVal) && COL_VAL_IS_NONE(pColVal) && !setNoneCol) {
         noneCol = iCol;
         setNoneCol = true;
@@ -1245,7 +1264,13 @@ static int32_t mergeLast(tb_uid_t uid, STsdb *pTsdb, SArray **ppLastArray) {
       for (iCol = 1; iCol < nCol; ++iCol) {
         tsdbRowGetColVal(pRow, pTSchema, iCol, pColVal);
 
-        if (taosArrayPush(pColArray, &(SLastCol){.ts = lastRowTs, .colVal = *pColVal}) == NULL) {
+        SLastCol lastCol = {.ts = lastRowTs, .colVal = *pColVal};
+        if (IS_VAR_DATA_TYPE(pColVal->type)) {
+          lastCol.colVal.value.pData = taosMemoryMalloc(lastCol.colVal.value.nData);
+          memcpy(lastCol.colVal.value.pData, pColVal->value.pData, pColVal->value.nData);
+        }
+
+        if (taosArrayPush(pColArray, &lastCol) == NULL) {
           code = TSDB_CODE_OUT_OF_MEMORY;
           goto _err;
         }
@@ -1272,7 +1297,16 @@ static int32_t mergeLast(tb_uid_t uid, STsdb *pTsdb, SArray **ppLastArray) {
 
       tsdbRowGetColVal(pRow, pTSchema, iCol, pColVal);
       if (!COL_VAL_IS_VALUE(tColVal) && COL_VAL_IS_VALUE(pColVal)) {
-        taosArraySet(pColArray, iCol, &(SLastCol){.ts = rowTs, .colVal = *pColVal});
+        SLastCol lastCol = {.ts = rowTs, .colVal = *pColVal};
+        if (IS_VAR_DATA_TYPE(pColVal->type)) {
+          SLastCol *pLastCol = (SLastCol *)taosArrayGet(pColArray, iCol);
+          taosMemoryFree(pLastCol->colVal.value.pData);
+
+          lastCol.colVal.value.pData = taosMemoryMalloc(lastCol.colVal.value.nData);
+          memcpy(lastCol.colVal.value.pData, pColVal->value.pData, pColVal->value.nData);
+        }
+
+        taosArraySet(pColArray, iCol, &lastCol);
       } else if (!COL_VAL_IS_VALUE(tColVal) && !COL_VAL_IS_VALUE(pColVal) && !setNoneCol) {
         noneCol = iCol;
         setNoneCol = true;

From 640338893df2ea7feb5cfe58f9b97b87cff4723a Mon Sep 17 00:00:00 2001
From: Minglei Jin <mljin@taosdata.com>
Date: Wed, 19 Oct 2022 15:01:49 +0800
Subject: [PATCH 17/24] tsdb/cache: handle OOM exceptions

---
 source/dnode/vnode/src/tsdb/tsdbCache.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/source/dnode/vnode/src/tsdb/tsdbCache.c b/source/dnode/vnode/src/tsdb/tsdbCache.c
index d4cca40b89..e2bc9d0bec 100644
--- a/source/dnode/vnode/src/tsdb/tsdbCache.c
+++ b/source/dnode/vnode/src/tsdb/tsdbCache.c
@@ -1144,6 +1144,7 @@ static int32_t mergeLastRow(tb_uid_t uid, STsdb *pTsdb, bool *dup, SArray **ppCo
 
       *pColVal = COL_VAL_VALUE(pTColumn->colId, pTColumn->type, (SValue){.val = lastRowTs});
       if (taosArrayPush(pColArray, &(SLastCol){.ts = lastRowTs, .colVal = *pColVal}) == NULL) {
+        terrno = TSDB_CODE_OUT_OF_MEMORY;
         code = TSDB_CODE_OUT_OF_MEMORY;
         goto _err;
       }
@@ -1154,6 +1155,11 @@ static int32_t mergeLastRow(tb_uid_t uid, STsdb *pTsdb, bool *dup, SArray **ppCo
         SLastCol lastCol = {.ts = lastRowTs, .colVal = *pColVal};
         if (IS_VAR_DATA_TYPE(pColVal->type)) {
           lastCol.colVal.value.pData = taosMemoryMalloc(lastCol.colVal.value.nData);
+          if (lastCol.colVal.value.pData == NULL) {
+            terrno = TSDB_CODE_OUT_OF_MEMORY;
+            code = TSDB_CODE_OUT_OF_MEMORY;
+            goto _err;
+          }
           memcpy(lastCol.colVal.value.pData, pColVal->value.pData, pColVal->value.nData);
         }
 
@@ -1194,6 +1200,11 @@ static int32_t mergeLastRow(tb_uid_t uid, STsdb *pTsdb, bool *dup, SArray **ppCo
           taosMemoryFree(pLastCol->colVal.value.pData);
 
           lastCol.colVal.value.pData = taosMemoryMalloc(lastCol.colVal.value.nData);
+          if (lastCol.colVal.value.pData == NULL) {
+            terrno = TSDB_CODE_OUT_OF_MEMORY;
+            code = TSDB_CODE_OUT_OF_MEMORY;
+            goto _err;
+          }
           memcpy(lastCol.colVal.value.pData, pColVal->value.pData, pColVal->value.nData);
         }
 
@@ -1267,6 +1278,11 @@ static int32_t mergeLast(tb_uid_t uid, STsdb *pTsdb, SArray **ppLastArray) {
         SLastCol lastCol = {.ts = lastRowTs, .colVal = *pColVal};
         if (IS_VAR_DATA_TYPE(pColVal->type)) {
           lastCol.colVal.value.pData = taosMemoryMalloc(lastCol.colVal.value.nData);
+          if (lastCol.colVal.value.pData == NULL) {
+            terrno = TSDB_CODE_OUT_OF_MEMORY;
+            code = TSDB_CODE_OUT_OF_MEMORY;
+            goto _err;
+          }
           memcpy(lastCol.colVal.value.pData, pColVal->value.pData, pColVal->value.nData);
         }
 
@@ -1303,6 +1319,11 @@ static int32_t mergeLast(tb_uid_t uid, STsdb *pTsdb, SArray **ppLastArray) {
           taosMemoryFree(pLastCol->colVal.value.pData);
 
           lastCol.colVal.value.pData = taosMemoryMalloc(lastCol.colVal.value.nData);
+          if (lastCol.colVal.value.pData == NULL) {
+            terrno = TSDB_CODE_OUT_OF_MEMORY;
+            code = TSDB_CODE_OUT_OF_MEMORY;
+            goto _err;
+          }
           memcpy(lastCol.colVal.value.pData, pColVal->value.pData, pColVal->value.nData);
         }
 

From 116d1451e4c3fb4488d29c4b79a007548ad6087a Mon Sep 17 00:00:00 2001
From: Haojun Liao <hjliao@taosdata.com>
Date: Wed, 19 Oct 2022 15:43:58 +0800
Subject: [PATCH 18/24] fix(query): do some internal refactor.

---
 source/dnode/vnode/src/tsdb/tsdbCacheRead.c   | 35 +++++++++++++------
 tests/script/tsim/parser/last_cache_query.sim |  5 +--
 2 files changed, 28 insertions(+), 12 deletions(-)

diff --git a/source/dnode/vnode/src/tsdb/tsdbCacheRead.c b/source/dnode/vnode/src/tsdb/tsdbCacheRead.c
index 53f8d5be16..99c314fa45 100644
--- a/source/dnode/vnode/src/tsdb/tsdbCacheRead.c
+++ b/source/dnode/vnode/src/tsdb/tsdbCacheRead.c
@@ -29,12 +29,14 @@ typedef struct SCacheRowsReader {
   SArray*   pTableList;  // table id list
 } SCacheRowsReader;
 
+#define HASTYPE(_type, _t)  (((_type) & (_t)) == (_t))
+
 static void saveOneRow(SArray* pRow, SSDataBlock* pBlock, SCacheRowsReader* pReader, const int32_t* slotIds,
                        void** pRes) {
   ASSERT(pReader->numOfCols <= taosArrayGetSize(pBlock->pDataBlock));
   int32_t numOfRows = pBlock->info.rows;
 
-  if ((pReader->type & CACHESCAN_RETRIEVE_LAST) == CACHESCAN_RETRIEVE_LAST) {
+  if (HASTYPE(pReader->type, CACHESCAN_RETRIEVE_LAST)) {
     for (int32_t i = 0; i < pReader->numOfCols; ++i) {
       SColumnInfoData* pColInfoData = taosArrayGet(pBlock->pDataBlock, i);
       SFirstLastRes*   p = (SFirstLastRes*)varDataVal(pRes[i]);
@@ -54,7 +56,7 @@ static void saveOneRow(SArray* pRow, SSDataBlock* pBlock, SCacheRowsReader* pRea
           if (IS_VAR_DATA_TYPE(pColVal->colVal.type)) {
             varDataSetLen(p->buf, pColVal->colVal.value.nData);
             memcpy(varDataVal(p->buf), pColVal->colVal.value.pData, pColVal->colVal.value.nData);
-            p->bytes = pColVal->colVal.value.nData + VARSTR_HEADER_SIZE;
+            p->bytes = pColVal->colVal.value.nData + VARSTR_HEADER_SIZE;   // binary needs to plus the header size
           } else {
             memcpy(p->buf, &pColVal->colVal.value, pReader->pSchema->columns[slotId].bytes);
             p->bytes = pReader->pSchema->columns[slotId].bytes;
@@ -62,12 +64,13 @@ static void saveOneRow(SArray* pRow, SSDataBlock* pBlock, SCacheRowsReader* pRea
         }
       }
 
+      // pColInfoData->info.bytes includes the VARSTR_HEADER_SIZE, need to substruct it
       p->hasResult = true;
-      varDataSetLen(pRes[i], pColInfoData->info.bytes);
+      varDataSetLen(pRes[i], pColInfoData->info.bytes - VARSTR_HEADER_SIZE);
       colDataAppend(pColInfoData, numOfRows, (const char*)pRes[i], false);
     }
   } else {
-    ASSERT((pReader->type & CACHESCAN_RETRIEVE_LAST_ROW) == CACHESCAN_RETRIEVE_LAST_ROW);
+    ASSERT(HASTYPE(pReader->type, CACHESCAN_RETRIEVE_LAST_ROW));
 
     for (int32_t i = 0; i < pReader->numOfCols; ++i) {
       SColumnInfoData* pColInfoData = taosArrayGet(pBlock->pDataBlock, i);
@@ -177,6 +180,13 @@ static int32_t doExtractCacheRow(SCacheRowsReader* pr, SLRUCache* lruCache, uint
   return code;
 }
 
+static void freeItem(void* pItem) {
+  SLastCol* pCol = (SLastCol*) pItem;
+  if (IS_VAR_DATA_TYPE(pCol->colVal.type)) {
+    taosMemoryFree(pCol->colVal.value.pData);
+  }
+}
+
 int32_t tsdbRetrieveCacheRows(void* pReader, SSDataBlock* pResBlock, const int32_t* slotIds, SArray* pTableUidList) {
   if (pReader == NULL || pResBlock == NULL) {
     return TSDB_CODE_INVALID_PARA;
@@ -217,7 +227,6 @@ int32_t tsdbRetrieveCacheRows(void* pReader, SSDataBlock* pResBlock, const int32
     if (IS_VAR_DATA_TYPE(pCol->type)) {
       p.colVal.value.pData = taosMemoryCalloc(pCol->bytes, sizeof(char));
     }
-
     taosArrayPush(pLastCols, &p);
   }
 
@@ -237,19 +246,25 @@ int32_t tsdbRetrieveCacheRows(void* pReader, SSDataBlock* pResBlock, const int32
 
       {
         for (int32_t k = 0; k < pr->numOfCols; ++k) {
-          SLastCol* p = taosArrayGet(pLastCols, k);
-          if (slotIds[k] == -1) {  // the primary timestamp
-            SLastCol* pCol = (SLastCol*)taosArrayGet(pRow, k);
+          int32_t slotId = slotIds[k];
+
+          if (slotId == -1) {  // the primary timestamp
+            SLastCol* p = taosArrayGet(pLastCols, 0);
+            SLastCol* pCol = (SLastCol*)taosArrayGet(pRow, 0);
             if (pCol->ts > p->ts) {
               hasRes = true;
               p->ts = pCol->ts;
               p->colVal = pCol->colVal;
             }
           } else {
-            int32_t   slotId = slotIds[k];
+            SLastCol* p = taosArrayGet(pLastCols, slotId);
             SLastCol* pColVal = (SLastCol*)taosArrayGet(pRow, slotId);
 
             if (pColVal->ts > p->ts) {
+              if (!COL_VAL_IS_VALUE(&pColVal->colVal) && HASTYPE(pr->type, CACHESCAN_RETRIEVE_LAST)) {
+                continue;
+              }
+
               hasRes = true;
               p->ts = pColVal->ts;
 
@@ -308,6 +323,6 @@ int32_t tsdbRetrieveCacheRows(void* pReader, SSDataBlock* pResBlock, const int32
   }
 
   taosMemoryFree(pRes);
-  taosArrayDestroy(pLastCols);
+  taosArrayDestroyEx(pLastCols, freeItem);
   return code;
 }
diff --git a/tests/script/tsim/parser/last_cache_query.sim b/tests/script/tsim/parser/last_cache_query.sim
index f32435960c..6cd5309590 100644
--- a/tests/script/tsim/parser/last_cache_query.sim
+++ b/tests/script/tsim/parser/last_cache_query.sim
@@ -39,6 +39,7 @@ if $data02 != 5.000000000 then
   return -1
 endi
 if $data03 != 3 then
+  print expect 3, actual: $data03
   return -1
 endi
 if $data04 != @70-01-01 07:59:57.000@ then
@@ -210,7 +211,7 @@ if $data01 != 6 then
   return -1
 endi
 if $data02 != 37.000000000 then
-  print $data02
+  print expect 37.000000000 actual: $data02
   return -1
 endi
 if $data03 != 27 then
@@ -233,7 +234,7 @@ if $data01 != 6 then
   return -1
 endi
 if $data02 != 37.000000000 then
-  print $data02
+  print expect 37.000000000, acutal: $data02
   return -1
 endi
 if $data03 != 27 then

From 325712fdf9454ffe19dca9a8333c656483f44408 Mon Sep 17 00:00:00 2001
From: Haojun Liao <hjliao@taosdata.com>
Date: Wed, 19 Oct 2022 15:54:43 +0800
Subject: [PATCH 19/24] fix(query): add some init functions.

---
 source/libs/executor/src/timewindowoperator.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/source/libs/executor/src/timewindowoperator.c b/source/libs/executor/src/timewindowoperator.c
index 1bcf274460..8792569f14 100644
--- a/source/libs/executor/src/timewindowoperator.c
+++ b/source/libs/executor/src/timewindowoperator.c
@@ -5492,9 +5492,13 @@ SOperatorInfo* createStreamIntervalOperatorInfo(SOperatorInfo* downstream, SPhys
   pInfo->ignoreExpiredData = pIntervalPhyNode->window.igExpired;
   pInfo->isFinal = false;
 
+  SExprSupp* pSup = &pOperator->exprSupp;
+  initBasicInfo(&pInfo->binfo, pResBlock);
+  initStreamFunciton(pSup->pCtx, pSup->numOfExprs);
+  initExecTimeWindowInfo(&pInfo->twAggSup.timeWindowData, &pTaskInfo->window);
+
   pInfo->primaryTsIndex = ((SColumnNode*)pIntervalPhyNode->window.pTspk)->slotId;
   initResultSizeInfo(&pOperator->resultInfo, 4096);
-  SExprSupp* pSup = &pOperator->exprSupp;
 
   if (pIntervalPhyNode->window.pExprs != NULL) {
     int32_t    numOfScalar = 0;

From 35e829dc28e4b262d9661a610d236c70942c9cb5 Mon Sep 17 00:00:00 2001
From: Xiaoyu Wang <xiaoyuwang@taosdata.com>
Date: Wed, 19 Oct 2022 15:58:51 +0800
Subject: [PATCH 20/24] fix: cache inapplicability

---
 source/libs/planner/src/planOptimizer.c | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/source/libs/planner/src/planOptimizer.c b/source/libs/planner/src/planOptimizer.c
index f5d32796b2..2e2e4e6dcf 100644
--- a/source/libs/planner/src/planOptimizer.c
+++ b/source/libs/planner/src/planOptimizer.c
@@ -2155,6 +2155,22 @@ static bool lastRowScanOptHasTag(SNode* pExpr) {
   return hasTag;
 }
 
+static bool hasSuitableCache(int8_t cacheLastMode, bool hasLastRow, bool hasLast) {
+  switch (cacheLastMode) {
+    case TSDB_CACHE_MODEL_NONE:
+      return false;
+    case TSDB_CACHE_MODEL_LAST_ROW:
+      return hasLastRow;
+    case TSDB_CACHE_MODEL_LAST_VALUE:
+      return hasLast;
+    case TSDB_CACHE_MODEL_BOTH:
+      return true;
+    default:
+      break;
+  }
+  return false;
+}
+
 static bool lastRowScanOptMayBeOptimized(SLogicNode* pNode) {
   if (QUERY_NODE_LOGIC_PLAN_AGG != nodeType(pNode) || 1 != LIST_LENGTH(pNode->pChildren) ||
       QUERY_NODE_LOGIC_PLAN_SCAN != nodeType(nodesListGetNode(pNode->pChildren, 0))) {
@@ -2165,7 +2181,8 @@ static bool lastRowScanOptMayBeOptimized(SLogicNode* pNode) {
   SScanLogicNode* pScan = (SScanLogicNode*)nodesListGetNode(pNode->pChildren, 0);
   // Only one of LAST and LASTROW can appear
   if (pAgg->hasLastRow == pAgg->hasLast || NULL != pAgg->pGroupKeys || NULL != pScan->node.pConditions ||
-      0 == pScan->cacheLastMode || IS_TSWINDOW_SPECIFIED(pScan->scanRange)) {
+      !hasSuitableCache(pScan->cacheLastMode, pAgg->hasLastRow, pAgg->hasLast) ||
+      IS_TSWINDOW_SPECIFIED(pScan->scanRange)) {
     return false;
   }
 

From 6dea891571dca633d930e24428b18ff9dc499674 Mon Sep 17 00:00:00 2001
From: Minglei Jin <mljin@taosdata.com>
Date: Wed, 19 Oct 2022 16:07:53 +0800
Subject: [PATCH 21/24] fix: release data file reader

---
 source/dnode/vnode/src/tsdb/tsdbCache.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/source/dnode/vnode/src/tsdb/tsdbCache.c b/source/dnode/vnode/src/tsdb/tsdbCache.c
index e2bc9d0bec..96504f343a 100644
--- a/source/dnode/vnode/src/tsdb/tsdbCache.c
+++ b/source/dnode/vnode/src/tsdb/tsdbCache.c
@@ -519,6 +519,11 @@ static int32_t getNextRowFromFSLast(void *iter, TSDBROW **ppRow) {
         return code;
       }
 
+      if (state->pDataFReader != NULL) {
+        tsdbDataFReaderClose(&state->pDataFReader);
+        state->pDataFReader = NULL;
+      }
+
       code = tsdbDataFReaderOpen(&state->pDataFReader, state->pTsdb, pFileSet);
       if (code) goto _err;
 
@@ -662,6 +667,8 @@ static int32_t getNextRowFromFS(void *iter, TSDBROW **ppRow) {
        */
       state->pBlockIdx = taosArraySearch(state->aBlockIdx, state->pBlockIdxExp, tCmprBlockIdx, TD_EQ);
       if (!state->pBlockIdx) {
+        tsdbDataFReaderClose(&state->pDataFReader);
+        state->pDataFReader = NULL;
         goto _next_fileset;
       }
 

From b20e2ed5afe9fc7f37fdf03686f8ca2c723b4122 Mon Sep 17 00:00:00 2001
From: Haojun Liao <hjliao@taosdata.com>
Date: Wed, 19 Oct 2022 17:43:23 +0800
Subject: [PATCH 22/24] fix(query): set correct last value.

---
 source/dnode/vnode/src/tsdb/tsdbCacheRead.c  | 30 ++++++++++++--------
 source/libs/executor/src/cachescanoperator.c | 17 ++++++-----
 tests/system-test/2-query/last_row.py        |  2 +-
 3 files changed, 29 insertions(+), 20 deletions(-)

diff --git a/source/dnode/vnode/src/tsdb/tsdbCacheRead.c b/source/dnode/vnode/src/tsdb/tsdbCacheRead.c
index 99c314fa45..1437811521 100644
--- a/source/dnode/vnode/src/tsdb/tsdbCacheRead.c
+++ b/source/dnode/vnode/src/tsdb/tsdbCacheRead.c
@@ -162,7 +162,7 @@ static int32_t doExtractCacheRow(SCacheRowsReader* pr, SLRUCache* lruCache, uint
   int32_t code = TSDB_CODE_SUCCESS;
   *pRow = NULL;
 
-  if ((pr->type & CACHESCAN_RETRIEVE_LAST_ROW) == CACHESCAN_RETRIEVE_LAST_ROW) {
+  if (HASTYPE(pr->type, CACHESCAN_RETRIEVE_LAST_ROW)) {
     code = tsdbCacheGetLastrowH(lruCache, uid, pr->pVnode->pTsdb, h);
   } else {
     code = tsdbCacheGetLastH(lruCache, uid, pr->pVnode->pTsdb, h);
@@ -231,7 +231,7 @@ int32_t tsdbRetrieveCacheRows(void* pReader, SSDataBlock* pResBlock, const int32
   }
 
   // retrieve the only one last row of all tables in the uid list.
-  if ((pr->type & CACHESCAN_RETRIEVE_TYPE_SINGLE) == CACHESCAN_RETRIEVE_TYPE_SINGLE) {
+  if (HASTYPE(pr->type, CACHESCAN_RETRIEVE_TYPE_SINGLE)) {
     for (int32_t i = 0; i < numOfTables; ++i) {
       STableKeyInfo* pKeyInfo = taosArrayGet(pr->pTableList, i);
 
@@ -255,6 +255,15 @@ int32_t tsdbRetrieveCacheRows(void* pReader, SSDataBlock* pResBlock, const int32
               hasRes = true;
               p->ts = pCol->ts;
               p->colVal = pCol->colVal;
+
+              // only set value for last row query
+              if (HASTYPE(pr->type, CACHESCAN_RETRIEVE_LAST_ROW)) {
+                if (taosArrayGetSize(pTableUidList) == 0) {
+                  taosArrayPush(pTableUidList, &pKeyInfo->uid);
+                } else {
+                  taosArraySet(pTableUidList, 0, &pKeyInfo->uid);
+                }
+              }
             }
           } else {
             SLastCol* p = taosArrayGet(pLastCols, slotId);
@@ -268,15 +277,12 @@ int32_t tsdbRetrieveCacheRows(void* pReader, SSDataBlock* pResBlock, const int32
               hasRes = true;
               p->ts = pColVal->ts;
 
-              if (COL_VAL_IS_VALUE(&pColVal->colVal)) {
-                if (IS_VAR_DATA_TYPE(pColVal->colVal.type)) {
-                  uint8_t* px = p->colVal.value.pData;
-                  p->colVal = pColVal->colVal;
-                  p->colVal.value.pData = px;
-                  memcpy(px, pColVal->colVal.value.pData, pColVal->colVal.value.nData);
-                } else {
-                  p->colVal = pColVal->colVal;
-                }
+              uint8_t* px = p->colVal.value.pData;
+              p->colVal = pColVal->colVal;
+
+              if (COL_VAL_IS_VALUE(&pColVal->colVal) && IS_VAR_DATA_TYPE(pColVal->colVal.type)) {
+                p->colVal.value.pData = px;
+                memcpy(px, pColVal->colVal.value.pData, pColVal->colVal.value.nData);
               }
             }
           }
@@ -290,7 +296,7 @@ int32_t tsdbRetrieveCacheRows(void* pReader, SSDataBlock* pResBlock, const int32
       saveOneRow(pLastCols, pResBlock, pr, slotIds, pRes);
     }
 
-  } else if ((pr->type & CACHESCAN_RETRIEVE_TYPE_ALL) == CACHESCAN_RETRIEVE_TYPE_ALL) {
+  } else if (HASTYPE(pr->type, CACHESCAN_RETRIEVE_TYPE_ALL)) {
     for (int32_t i = pr->tableIndex; i < numOfTables; ++i) {
       STableKeyInfo* pKeyInfo = taosArrayGet(pr->pTableList, i);
       code = doExtractCacheRow(pr, lruCache, pKeyInfo->uid, &pRow, &h);
diff --git a/source/libs/executor/src/cachescanoperator.c b/source/libs/executor/src/cachescanoperator.c
index 5d63892b7b..814f3871db 100644
--- a/source/libs/executor/src/cachescanoperator.c
+++ b/source/libs/executor/src/cachescanoperator.c
@@ -193,20 +193,23 @@ SSDataBlock* doScanCache(SOperatorInfo* pOperator) {
       pInfo->currentGroupIndex += 1;
 
       // check for tag values
-      // TODO NOTE: The uid of pInfo->pRes is required.
       if (pInfo->pRes->info.rows > 0) {
         if (pInfo->pseudoExprSup.numOfExprs > 0) {
           SExprSupp* pSup = &pInfo->pseudoExprSup;
-          pInfo->pRes->info.uid = *(tb_uid_t*)taosArrayGet(pInfo->pUidList, 0);
 
           STableKeyInfo* pKeyInfo = taosArrayGet(pGroupTableList, 0);
           pInfo->pRes->info.groupId = pKeyInfo->groupId;
 
-          code = addTagPseudoColumnData(&pInfo->readHandle, pSup->pExprInfo, pSup->numOfExprs, pInfo->pRes,
-                                        GET_TASKID(pTaskInfo));
-          if (code != TSDB_CODE_SUCCESS) {
-            pTaskInfo->code = code;
-            return NULL;
+          if (taosArrayGetSize(pInfo->pUidList) > 0) {
+            ASSERT((pInfo->retrieveType & CACHESCAN_RETRIEVE_LAST_ROW) == CACHESCAN_RETRIEVE_LAST_ROW);
+
+            pInfo->pRes->info.uid = *(tb_uid_t*)taosArrayGet(pInfo->pUidList, 0);
+            code = addTagPseudoColumnData(&pInfo->readHandle, pSup->pExprInfo, pSup->numOfExprs, pInfo->pRes,
+                                          GET_TASKID(pTaskInfo));
+            if (code != TSDB_CODE_SUCCESS) {
+              pTaskInfo->code = code;
+              return NULL;
+            }
           }
         }
 
diff --git a/tests/system-test/2-query/last_row.py b/tests/system-test/2-query/last_row.py
index 5d435b068f..6286852641 100644
--- a/tests/system-test/2-query/last_row.py
+++ b/tests/system-test/2-query/last_row.py
@@ -13,7 +13,7 @@ class TDTestCase:
 
     def init(self, conn, logSql):
         tdLog.debug(f"start to excute {__file__}")
-        tdSql.init(conn.cursor(), False)
+        tdSql.init(conn.cursor(), True)
         self.tb_nums = 10
         self.row_nums = 20
         self.ts = 1434938400000

From 60b85028afe7ca9b609d47f2afafd1d24c2f7bb7 Mon Sep 17 00:00:00 2001
From: Minglei Jin <mljin@taosdata.com>
Date: Wed, 19 Oct 2022 18:53:51 +0800
Subject: [PATCH 23/24] fix: do not copy binary when nData is 0

---
 source/dnode/vnode/src/tsdb/tsdbCache.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/source/dnode/vnode/src/tsdb/tsdbCache.c b/source/dnode/vnode/src/tsdb/tsdbCache.c
index 96504f343a..bb394e8acc 100644
--- a/source/dnode/vnode/src/tsdb/tsdbCache.c
+++ b/source/dnode/vnode/src/tsdb/tsdbCache.c
@@ -61,7 +61,7 @@ static void deleteTableCacheLast(const void *key, size_t keyLen, void *value) {
   int16_t nCol = taosArrayGetSize(pLastArray);
   for (int16_t iCol = 0; iCol < nCol; ++iCol) {
     SLastCol *pLastCol = (SLastCol *)taosArrayGet(pLastArray, iCol);
-    if (IS_VAR_DATA_TYPE(pLastCol->colVal.type)) {
+    if (IS_VAR_DATA_TYPE(pLastCol->colVal.type) && pLastCol->colVal.value.nData > 0) {
       taosMemoryFree(pLastCol->colVal.value.pData);
     }
   }
@@ -1160,7 +1160,7 @@ static int32_t mergeLastRow(tb_uid_t uid, STsdb *pTsdb, bool *dup, SArray **ppCo
         tsdbRowGetColVal(pRow, pTSchema, iCol, pColVal);
 
         SLastCol lastCol = {.ts = lastRowTs, .colVal = *pColVal};
-        if (IS_VAR_DATA_TYPE(pColVal->type)) {
+        if (IS_VAR_DATA_TYPE(pColVal->type) && pColVal->value.nData > 0) {
           lastCol.colVal.value.pData = taosMemoryMalloc(lastCol.colVal.value.nData);
           if (lastCol.colVal.value.pData == NULL) {
             terrno = TSDB_CODE_OUT_OF_MEMORY;
@@ -1202,7 +1202,7 @@ static int32_t mergeLastRow(tb_uid_t uid, STsdb *pTsdb, bool *dup, SArray **ppCo
       tsdbRowGetColVal(pRow, pTSchema, iCol, pColVal);
       if (COL_VAL_IS_NONE(tColVal) && !COL_VAL_IS_NONE(pColVal)) {
         SLastCol lastCol = {.ts = rowTs, .colVal = *pColVal};
-        if (IS_VAR_DATA_TYPE(pColVal->type)) {
+        if (IS_VAR_DATA_TYPE(pColVal->type) && pColVal->value.nData > 0) {
           SLastCol *pLastCol = (SLastCol *)taosArrayGet(pColArray, iCol);
           taosMemoryFree(pLastCol->colVal.value.pData);
 
@@ -1283,7 +1283,7 @@ static int32_t mergeLast(tb_uid_t uid, STsdb *pTsdb, SArray **ppLastArray) {
         tsdbRowGetColVal(pRow, pTSchema, iCol, pColVal);
 
         SLastCol lastCol = {.ts = lastRowTs, .colVal = *pColVal};
-        if (IS_VAR_DATA_TYPE(pColVal->type)) {
+        if (IS_VAR_DATA_TYPE(pColVal->type) && pColVal->value.nData > 0) {
           lastCol.colVal.value.pData = taosMemoryMalloc(lastCol.colVal.value.nData);
           if (lastCol.colVal.value.pData == NULL) {
             terrno = TSDB_CODE_OUT_OF_MEMORY;
@@ -1321,7 +1321,7 @@ static int32_t mergeLast(tb_uid_t uid, STsdb *pTsdb, SArray **ppLastArray) {
       tsdbRowGetColVal(pRow, pTSchema, iCol, pColVal);
       if (!COL_VAL_IS_VALUE(tColVal) && COL_VAL_IS_VALUE(pColVal)) {
         SLastCol lastCol = {.ts = rowTs, .colVal = *pColVal};
-        if (IS_VAR_DATA_TYPE(pColVal->type)) {
+        if (IS_VAR_DATA_TYPE(pColVal->type) && pColVal->value.nData > 0) {
           SLastCol *pLastCol = (SLastCol *)taosArrayGet(pColArray, iCol);
           taosMemoryFree(pLastCol->colVal.value.pData);
 

From b3658f983f4ceecb7f789c49c823039fa2b21217 Mon Sep 17 00:00:00 2001
From: Xiaoyu Wang <xiaoyuwang@taosdata.com>
Date: Thu, 20 Oct 2022 14:35:34 +0800
Subject: [PATCH 24/24] fix: last constant error

---
 source/libs/planner/src/planOptimizer.c | 24 ++++++++++++++++--------
 1 file changed, 16 insertions(+), 8 deletions(-)

diff --git a/source/libs/planner/src/planOptimizer.c b/source/libs/planner/src/planOptimizer.c
index 2e2e4e6dcf..3171bb531b 100644
--- a/source/libs/planner/src/planOptimizer.c
+++ b/source/libs/planner/src/planOptimizer.c
@@ -2139,20 +2139,28 @@ static int32_t rewriteUniqueOptimize(SOptimizeContext* pCxt, SLogicSubplan* pLog
   return rewriteUniqueOptimizeImpl(pCxt, pLogicSubplan, pIndef);
 }
 
-static EDealRes lastRowScanOptHasTagImpl(SNode* pNode, void* pContext) {
+typedef struct SLastRowScanOptLastParaCkCxt {
+  bool hasTag;
+  bool hasCol;
+} SLastRowScanOptLastParaCkCxt;
+
+static EDealRes lastRowScanOptLastParaCheckImpl(SNode* pNode, void* pContext) {
   if (QUERY_NODE_COLUMN == nodeType(pNode)) {
+    SLastRowScanOptLastParaCkCxt* pCxt = pContext;
     if (COLUMN_TYPE_TAG == ((SColumnNode*)pNode)->colType || COLUMN_TYPE_TBNAME == ((SColumnNode*)pNode)->colType) {
-      *(bool*)pContext = true;
-      return DEAL_RES_END;
+      pCxt->hasTag = true;
+    } else {
+      pCxt->hasCol = true;
     }
+    return DEAL_RES_END;
   }
   return DEAL_RES_CONTINUE;
 }
 
-static bool lastRowScanOptHasTag(SNode* pExpr) {
-  bool hasTag = false;
-  nodesWalkExpr(pExpr, lastRowScanOptHasTagImpl, &hasTag);
-  return hasTag;
+static bool lastRowScanOptLastParaCheck(SNode* pExpr) {
+  SLastRowScanOptLastParaCkCxt cxt = {.hasTag = false, .hasCol = false};
+  nodesWalkExpr(pExpr, lastRowScanOptLastParaCheckImpl, &cxt);
+  return !cxt.hasTag && cxt.hasCol;
 }
 
 static bool hasSuitableCache(int8_t cacheLastMode, bool hasLastRow, bool hasLast) {
@@ -2192,7 +2200,7 @@ static bool lastRowScanOptMayBeOptimized(SLogicNode* pNode) {
   FOREACH(pFunc, ((SAggLogicNode*)pNode)->pAggFuncs) {
     SFunctionNode* pAggFunc = (SFunctionNode*)pFunc;
     if (FUNCTION_TYPE_LAST == pAggFunc->funcType) {
-      if (hasSelectFunc || lastRowScanOptHasTag(nodesListGetNode(pAggFunc->pParameterList, 0))) {
+      if (hasSelectFunc || !lastRowScanOptLastParaCheck(nodesListGetNode(pAggFunc->pParameterList, 0))) {
         return false;
       }
       hasLastFunc = true;