add cache last null columns feature

documentation20/cn/11.administrator/docs.md

@@ -129,7 +129,7 @@ taosd -C
 - blocks：每个VNODE（TSDB）中有多少cache大小的内存块。因此一个VNODE的用的内存大小粗略为（cache * blocks）。单位为块，默认值：4。（可通过 alter database 修改）
 - replica：副本个数，取值范围：1-3。单位为个，默认值：1。（可通过 alter database 修改）
 - precision：时间戳精度标识，ms表示毫秒，us表示微秒。默认值：ms。
-- cacheLast：是否在内存中缓存子表 last_row，0：关闭；1：开启。默认值：0。（可通过 alter database 修改）（从 2.0.11 版本开始支持此参数）
+- cacheLast：是否在内存中缓存子表的最近数据，0：关闭；1：缓存子表最近一行数据；2：缓存子表每一列的最近的非NULL值，设置为3表示同时开启了1和2。默认值：0。（可通过 alter database 修改）（从 2.0.11 版本开始支持此参数）
 
 对于一个应用场景，可能有多种数据特征的数据并存，最佳的设计是将具有相同数据特征的表放在一个库里，这样一个应用有多个库，而每个库可以配置不同的存储参数，从而保证系统有最优的性能。TDengine允许应用在创建库时指定上述存储参数，如果指定，该参数就将覆盖对应的系统配置参数。举例，有下述SQL：
 

src/common/src/ttypes.c

@@ -417,6 +417,16 @@ void setVardataNull(char* val, int32_t type) {
   }
 }
 
+bool isVardataNull(char* val, int32_t type) {
+  if (type == TSDB_DATA_TYPE_BINARY) {
+    return *(uint8_t*) varDataVal(val) == TSDB_DATA_BINARY_NULL;
+  } else if (type == TSDB_DATA_TYPE_NCHAR) {
+    return *(uint32_t*) varDataVal(val) == TSDB_DATA_NCHAR_NULL;
+  } else {
+    assert(0);
+  }
+}
+
 void setNull(char *val, int32_t type, int32_t bytes) { setNullN(val, type, bytes, 1); }
 
 void setNullN(char *val, int32_t type, int32_t bytes, int32_t numOfElems) {
@@ -492,6 +502,54 @@ void setNullN(char *val, int32_t type, int32_t bytes, int32_t numOfElems) {
   }
 }
 
+bool isNullN(char *val, int32_t type) {
+  switch (type) {
+    case TSDB_DATA_TYPE_BOOL:
+      return *(uint8_t *)(val) == TSDB_DATA_BOOL_NULL;
+      break;
+    case TSDB_DATA_TYPE_TINYINT:
+      return *(uint8_t *)(val) == TSDB_DATA_TINYINT_NULL;
+      break;
+    case TSDB_DATA_TYPE_SMALLINT:
+      return *(uint16_t *)(val) == TSDB_DATA_SMALLINT_NULL;
+      break;
+    case TSDB_DATA_TYPE_INT:
+      return *(uint32_t *)(val) == TSDB_DATA_INT_NULL;
+      break;
+    case TSDB_DATA_TYPE_BIGINT:
+    case TSDB_DATA_TYPE_TIMESTAMP:
+      return *(uint64_t *)(val) == TSDB_DATA_BIGINT_NULL;
+      break;
+    case TSDB_DATA_TYPE_UTINYINT:
+      return *(uint8_t *)(val) == TSDB_DATA_UTINYINT_NULL;
+      break;
+    case TSDB_DATA_TYPE_USMALLINT:
+      return *(uint16_t *)(val) == TSDB_DATA_USMALLINT_NULL;
+      break;
+    case TSDB_DATA_TYPE_UINT:
+      return *(uint32_t *)(val) == TSDB_DATA_UINT_NULL;
+      break;
+    case TSDB_DATA_TYPE_UBIGINT:
+      return *(uint64_t *)(val) == TSDB_DATA_UBIGINT_NULL;
+      break;
+    case TSDB_DATA_TYPE_FLOAT:
+      return *(uint32_t *)(val) == TSDB_DATA_FLOAT_NULL;
+      break;
+    case TSDB_DATA_TYPE_DOUBLE:
+      return *(uint64_t *)(val) == TSDB_DATA_DOUBLE_NULL;
+      break;
+    case TSDB_DATA_TYPE_NCHAR:
+    case TSDB_DATA_TYPE_BINARY:
+      return isVardataNull(val, type);
+      break;
+    default: {
+      return *(uint32_t *)(val) == TSDB_DATA_INT_NULL;
+      break;
+    }
+  }
+
+}
+
 static uint8_t   nullBool     = TSDB_DATA_BOOL_NULL;
 static uint8_t   nullTinyInt  = TSDB_DATA_TINYINT_NULL;
 static uint16_t  nullSmallInt = TSDB_DATA_SMALLINT_NULL;

src/inc/taosdef.h

@@ -299,7 +299,7 @@ do { \
 #define TSDB_DEFAULT_DB_UPDATE_OPTION   0
 
 #define TSDB_MIN_DB_CACHE_LAST_ROW      0
-#define TSDB_MAX_DB_CACHE_LAST_ROW      1
+#define TSDB_MAX_DB_CACHE_LAST_ROW      2
 #define TSDB_DEFAULT_CACHE_LAST_ROW     0
 
 #define TSDB_MIN_FSYNC_PERIOD           0

src/inc/tsdb.h

@@ -69,9 +69,13 @@ typedef struct {
   int8_t  precision;
   int8_t  compression;
   int8_t  update;
-  int8_t  cacheLastRow;
+  int8_t  cacheLastRow;    // 0:no cache, 1: cache last row, 2: cache last NULL column
 } STsdbCfg;
 
+#define CACHE_NO_LAST(c)          ((c)->cacheLastRow == 0)
+#define CACHE_LAST_ROW(c)         (((c)->cacheLastRow & 1) > 0)
+#define CACHE_LAST_NULL_COLUMN(c) (((c)->cacheLastRow & 2) > 0)
+
 // --------- TSDB REPOSITORY USAGE STATISTICS
 typedef struct {
   int64_t totalStorage;  // total bytes occupie

src/inc/ttype.h

@@ -176,6 +176,9 @@ void  setNull(char *val, int32_t type, int32_t bytes);
 void  setNullN(char *val, int32_t type, int32_t bytes, int32_t numOfElems);
 void *getNullValue(int32_t type);
 
+bool isVardataNull(char* val, int32_t type);
+bool isNullN(char *val, int32_t type);
+
 void assignVal(char *val, const char *src, int32_t len, int32_t type);
 void tsDataSwap(void *pLeft, void *pRight, int32_t type, int32_t size, void* buf);
 

src/tsdb/inc/tsdbMeta.h

@@ -36,6 +36,9 @@ typedef struct STable {
   char*          sql;
   void*          cqhandle;
   SRWLatch       latch;  // TODO: implementa latch functions
+
+  SDataCol      *lastCols;
+  int32_t        lastColNum;
   T_REF_DECLARE()
 } STable;
 

src/tsdb/src/tsdbMain.c

@@ -447,8 +447,10 @@ static int32_t tsdbCheckAndSetDefaultCfg(STsdbCfg *pCfg) {
   if (pCfg->update != 0) pCfg->update = 1;
 
   // update cacheLastRow
-  if (pCfg->cacheLastRow != 0) pCfg->cacheLastRow = 1;
-
+  if (pCfg->cacheLastRow != 0) {
+    if (pCfg->cacheLastRow > 3)
+      pCfg->cacheLastRow = 1;
+  }
   return 0;
 }
 
@@ -581,7 +583,7 @@ int tsdbRestoreInfo(STsdbRepo *pRepo) {
       if (pIdx && lastKey < pIdx->maxKey) {
         pTable->lastKey = pIdx->maxKey;
 
-        if (pCfg->cacheLastRow) {
+        if (CACHE_LAST_ROW(pCfg)) {
           if (tsdbLoadBlockInfo(&readh, NULL) < 0) {
             tsdbDestroyReadH(&readh);
             return -1;

src/tsdb/src/tsdbMemTable.c

@@ -955,11 +955,61 @@ static void tsdbFreeRows(STsdbRepo *pRepo, void **rows, int rowCounter) {
   }
 }
 
+static void updateTableLatestColumn(STsdbRepo *pRepo, STable *pTable, SDataRow row) {
+  //tsdbDebug("vgId:%d updateTableLatestColumn, row version:%d", REPO_ID(pRepo), dataRowVersion(row));
+
+  if (pTable->numOfSchemas <= 0) {
+    return;
+  }
+  STSchema* pSchema = pTable->schema[pTable->numOfSchemas - 1];
+  int i = pTable->numOfSchemas - 1;
+  while ((pSchema == NULL || pSchema->version != dataRowVersion(row)) && i >= 0) {
+    i -= 1;
+    pSchema = pTable->schema[i];
+  }
+  if (pSchema == NULL || pSchema->version != dataRowVersion(row)) {
+    return;
+  }
+
+  SDataCol *pLatestCols = pTable->lastCols;
+
+  for (int j = 0; j < schemaNCols(pSchema); j++) {
+    if (j >= pTable->lastColNum) {
+      pTable->lastCols = realloc(pTable->lastCols, pTable->lastColNum + 10);
+      for (int i = 0; i < 10; ++i) {
+        pTable->lastCols[i + pTable->lastColNum].bytes = 0;
+        pTable->lastCols[i + pTable->lastColNum].pData = NULL;
+      }
+      pTable->lastColNum += 10;
+    }
+
+    STColumn *pTCol = schemaColAt(pSchema, j);
+    SDataCol *pDataCol = &(pLatestCols[j]);
+    void* value = tdGetRowDataOfCol(row, (int8_t)pTCol->type, TD_DATA_ROW_HEAD_SIZE + pSchema->columns[j].offset);
+    if (isNullN(value, pTCol->type)) {
+      continue;
+    }
+    if (pDataCol->pData == NULL) {
+      pDataCol->pData = malloc(pSchema->columns[j].bytes);
+      pDataCol->bytes = pSchema->columns[j].bytes;
+    } else if (pDataCol->bytes < pSchema->columns[j].bytes) {
+      pDataCol->pData = realloc(pDataCol->pData, pSchema->columns[j].bytes);
+      pDataCol->bytes = pSchema->columns[j].bytes;
+    }
+
+    //tsdbDebug("vgId:%d cache column %d for %d,%p", REPO_ID(pRepo), j, pDataCol->bytes, pDataCol->pData);
+
+    memcpy(pDataCol->pData, value, pDataCol->bytes);
+  }
+}
+
 static int tsdbUpdateTableLatestInfo(STsdbRepo *pRepo, STable *pTable, SDataRow row) {
   STsdbCfg *pCfg = &pRepo->config;
 
+  tsdbDebug("vgId:%d tsdbUpdateTableLatestInfo, %ld, %ld, %d", REPO_ID(pRepo), tsdbGetTableLastKeyImpl(pTable), dataRowKey(row), pCfg->cacheLastRow);
+
   if (tsdbGetTableLastKeyImpl(pTable) < dataRowKey(row)) {
-    if (pCfg->cacheLastRow || pTable->lastRow != NULL) {
+    if (CACHE_LAST_ROW(pCfg) || pTable->lastRow != NULL) {
       SDataRow nrow = pTable->lastRow;
       if (taosTSizeof(nrow) < dataRowLen(row)) {
         SDataRow orow = nrow;
@@ -984,7 +1034,10 @@ static int tsdbUpdateTableLatestInfo(STsdbRepo *pRepo, STable *pTable, SDataRow
     } else {
       pTable->lastKey = dataRowKey(row);
     }
-  }
 
+    if (CACHE_LAST_NULL_COLUMN(pCfg)) {
+      updateTableLatestColumn(pRepo, pTable, row);
+    }
+  }
   return 0;
 }

src/tsdb/src/tsdbMeta.c

@@ -14,6 +14,7 @@
  */
 #include "tsdbint.h"
 
+#define TSDB_LATEST_COLUMN_ARRAY_SIZE 20
 #define TSDB_SUPER_TABLE_SL_LEVEL 5
 #define DEFAULT_TAG_INDEX_COLUMN 0
 
@@ -671,6 +672,12 @@ static STable *tsdbNewTable() {
   }
 
   pTable->lastKey = TSKEY_INITIAL_VAL;
+  pTable->lastCols = (SDataCol*)malloc(TSDB_LATEST_COLUMN_ARRAY_SIZE * sizeof(SDataCol));
+  pTable->lastColNum = TSDB_LATEST_COLUMN_ARRAY_SIZE;
+  for (int i = 0; i < pTable->lastColNum; ++i) {
+    pTable->lastCols[i].bytes = 0;
+    pTable->lastCols[i].pData = NULL;
+  }
 
   return pTable;
 }