[FEAT MERGE] implement dynamic sampling

src/share/system_variable/ob_sys_var_class_type.h

@@ -248,6 +248,7 @@ enum ObSysVarClassType
   SYS_VAR_PARALLEL_DEGREE_POLICY = 10142,
   SYS_VAR_PARALLEL_DEGREE_LIMIT = 10143,
   SYS_VAR_PARALLEL_MIN_SCAN_TIME_THRESHOLD = 10144,
+  SYS_VAR_OPTIMIZER_DYNAMIC_SAMPLING = 10145,
 };
 
 }

src/share/system_variable/ob_system_variable_alias.h

@@ -243,6 +243,7 @@ namespace share
   static const char* const OB_SV_PARALLEL_DEGREE_POLICY = "parallel_degree_policy";
   static const char* const OB_SV_PARALLEL_DEGREE_LIMIT = "parallel_degree_limit";
   static const char* const OB_SV_PARALLEL_MIN_SCAN_TIME_THRESHOLD = "parallel_min_scan_time_threshold";
+  static const char* const OB_SV_OPTIMIZER_DYNAMIC_SAMPLING = "optimizer_dynamic_sampling";
 
 }
 }

src/share/system_variable/ob_system_variable_factory.cpp

@@ -278,6 +278,7 @@ const char *ObSysVarFactory::SYS_VAR_NAMES_SORTED_BY_NAME[] = {
   "ob_trx_lock_timeout",
   "ob_trx_timeout",
   "optimizer_capture_sql_plan_baselines",
+  "optimizer_dynamic_sampling",
   "optimizer_use_sql_plan_baselines",
   "parallel_degree_limit",
   "parallel_degree_policy",
@@ -508,6 +509,7 @@ const ObSysVarClassType ObSysVarFactory::SYS_VAR_IDS_SORTED_BY_NAME[] = {
   SYS_VAR_OB_TRX_LOCK_TIMEOUT,
   SYS_VAR_OB_TRX_TIMEOUT,
   SYS_VAR_OPTIMIZER_CAPTURE_SQL_PLAN_BASELINES,
+  SYS_VAR_OPTIMIZER_DYNAMIC_SAMPLING,
   SYS_VAR_OPTIMIZER_USE_SQL_PLAN_BASELINES,
   SYS_VAR_PARALLEL_DEGREE_LIMIT,
   SYS_VAR_PARALLEL_DEGREE_POLICY,
@@ -809,7 +811,8 @@ const char *ObSysVarFactory::SYS_VAR_NAMES_SORTED_BY_ID[] = {
   "_force_order_preserve_set",
   "parallel_degree_policy",
   "parallel_degree_limit",
-  "parallel_min_scan_time_threshold"
+  "parallel_min_scan_time_threshold",
+  "optimizer_dynamic_sampling"
 };
 
 bool ObSysVarFactory::sys_var_name_case_cmp(const char *name1, const ObString &name2)
@@ -1204,6 +1207,7 @@ int ObSysVarFactory::create_all_sys_vars()
         + sizeof(ObSysVarParallelDegreePolicy)
         + sizeof(ObSysVarParallelDegreeLimit)
         + sizeof(ObSysVarParallelMinScanTimeThreshold)
+        + sizeof(ObSysVarOptimizerDynamicSampling)
         ;
     void *ptr = NULL;
     if (OB_ISNULL(ptr = allocator_.alloc(total_mem_size))) {
@@ -3255,6 +3259,15 @@ int ObSysVarFactory::create_all_sys_vars()
         ptr = (void *)((char *)ptr + sizeof(ObSysVarParallelMinScanTimeThreshold));
       }
     }
+    if (OB_SUCC(ret)) {
+      if (OB_ISNULL(sys_var_ptr = new (ptr)ObSysVarOptimizerDynamicSampling())) {
+        ret = OB_ALLOCATE_MEMORY_FAILED;
+        LOG_ERROR("fail to new ObSysVarOptimizerDynamicSampling", K(ret));
+      } else {
+        store_buf_[ObSysVarsToIdxMap::get_store_idx(static_cast<int64_t>(SYS_VAR_OPTIMIZER_DYNAMIC_SAMPLING))] = sys_var_ptr;
+        ptr = (void *)((char *)ptr + sizeof(ObSysVarOptimizerDynamicSampling));
+      }
+    }
 
   }
   return ret;
@@ -5778,6 +5791,17 @@ int ObSysVarFactory::create_sys_var(ObSysVarClassType sys_var_id, ObBasicSysVar
       }
       break;
     }
+    case SYS_VAR_OPTIMIZER_DYNAMIC_SAMPLING: {
+      void *ptr = NULL;
+      if (OB_ISNULL(ptr = allocator_.alloc(sizeof(ObSysVarOptimizerDynamicSampling)))) {
+        ret = OB_ALLOCATE_MEMORY_FAILED;
+        LOG_ERROR("fail to alloc memory", K(ret), K(sizeof(ObSysVarOptimizerDynamicSampling)));
+      } else if (OB_ISNULL(sys_var_ptr = new (ptr)ObSysVarOptimizerDynamicSampling())) {
+        ret = OB_ALLOCATE_MEMORY_FAILED;
+        LOG_ERROR("fail to new ObSysVarOptimizerDynamicSampling", K(ret));
+      }
+      break;
+    }
 
     default: {
       ret = OB_ERR_UNEXPECTED;

src/share/system_variable/ob_system_variable_factory.h

@@ -1642,6 +1642,13 @@ public:
   inline virtual ObSysVarClassType get_type() const { return SYS_VAR_PARALLEL_MIN_SCAN_TIME_THRESHOLD; }
   inline virtual const common::ObObj &get_global_default_value() const { return ObSysVariables::get_default_value(226); }
 };
+class ObSysVarOptimizerDynamicSampling : public ObIntSysVar
+{
+public:
+  ObSysVarOptimizerDynamicSampling() : ObIntSysVar(NULL, NULL, NULL, NULL, NULL) {}
+  inline virtual ObSysVarClassType get_type() const { return SYS_VAR_OPTIMIZER_DYNAMIC_SAMPLING; }
+  inline virtual const common::ObObj &get_global_default_value() const { return ObSysVariables::get_default_value(227); }
+};
 
 
 class ObSysVarFactory
@@ -1661,7 +1668,7 @@ public:
   static const common::ObString get_sys_var_name_by_id(ObSysVarClassType sys_var_id);
 
   const static int64_t MYSQL_SYS_VARS_COUNT = 97;
-  const static int64_t OB_SYS_VARS_COUNT = 130;
+  const static int64_t OB_SYS_VARS_COUNT = 131;
   const static int64_t ALL_SYS_VARS_COUNT = MYSQL_SYS_VARS_COUNT + OB_SYS_VARS_COUNT;
 
   const static int16_t OB_SPECIFIC_SYS_VAR_ID_OFFSET = 10000;

src/share/system_variable/ob_system_variable_init.cpp

@@ -2980,13 +2980,27 @@ static struct VarsInit{
     ObSysVars[226].alias_ = "OB_SV_PARALLEL_MIN_SCAN_TIME_THRESHOLD" ;
     }();
 
+    [&] (){
+      ObSysVars[227].info_ = "control optimizer dynamic sample level" ;
+      ObSysVars[227].name_ = "optimizer_dynamic_sampling" ;
+      ObSysVars[227].data_type_ = ObUInt64Type ;
+      ObSysVars[227].value_ = "1" ;
+      ObSysVars[227].min_val_ = "0" ;
+      ObSysVars[227].max_val_ = "1" ;
+      ObSysVars[227].flags_ = ObSysVarFlag::GLOBAL_SCOPE | ObSysVarFlag::SESSION_SCOPE | ObSysVarFlag::NEED_SERIALIZE ;
+      ObSysVars[227].id_ = SYS_VAR_OPTIMIZER_DYNAMIC_SAMPLING ;
+      cur_max_var_id = MAX(cur_max_var_id, static_cast<int64_t>(SYS_VAR_OPTIMIZER_DYNAMIC_SAMPLING)) ;
+      ObSysVarsIdToArrayIdx[SYS_VAR_OPTIMIZER_DYNAMIC_SAMPLING] = 227 ;
+    ObSysVars[227].alias_ = "OB_SV_OPTIMIZER_DYNAMIC_SAMPLING" ;
+    }();
+
     if (cur_max_var_id >= ObSysVarFactory::OB_MAX_SYS_VAR_ID) { 
       HasInvalidSysVar = true;
     }
   }
 }vars_init;
 
-static int64_t var_amount = 227;
+static int64_t var_amount = 228;
 
 int64_t ObSysVariables::get_all_sys_var_count(){ return ObSysVarFactory::ALL_SYS_VARS_COUNT;}
 ObSysVarClassType ObSysVariables::get_sys_var_id(int64_t i){ return ObSysVars[i].id_;}

src/share/system_variable/ob_system_variable_init.json

@@ -3012,5 +3012,19 @@
     "info_cn": "使用 Auto DOP 策略时, 增大基表扫描并行度参考执行时间, 单位 ms",
     "background_cn": "",
     "ref_url": ""
+  },
+  "optimizer_dynamic_sampling": {
+    "id": 10145,
+    "name": "optimizer_dynamic_sampling",
+    "value": "1",
+    "data_type": "uint",
+    "min_val": "0",
+    "max_val": "1",
+    "info": "control optimizer dynamic sample level",
+    "flags": "GLOBAL | SESSION | NEED_SERIALIZE",
+    "publish_version": "420",
+    "info_cn": "",
+    "background_cn": "",
+    "ref_url": "?singleDoc#"
   }
 }