(3) 优化器(Query Optimizer):优化器是对逻辑执行计划进行优化 (4) 执行器(Executor):执行器是调用底层的运行框架执行逻辑执行计划 1. 2. 3. 4. 5. 6. 7. 2、执行流程 Hive QL 通过命令行或者客户端提交,经过 Compiler 编译器,运用 MetaStore 中的元数据进行类型检测和语法分析,生成一个逻辑方案(Logical ...
设置参数“setjoin__cache__level=4;setoptimizer__switch='join__cache__hashed=on';”后,MariaDB中的优化器会智能选择hashjoin算法。该说法是否正确()是否
设置参数“set join__cache__level = 4;set optimizer__switch=join__cache__hashed=on;”后,MariaDB中的优化器会智能选择hash join算法。该说法是否正确()
OptimizerHint OptimizerHintKind OptionState OptionValue OrderBulkInsertOption OrderByClause OrderIndexOption OutputClause OutputIntoClause OverClause PageVerifyDatabaseOption PageVerifyDatabaseOptionKind ParameterizationDatabaseOption ParameterizedDataTypeReference ParameterlessCall ParameterlessCallType ParameterModifier Param...
Proposes a parallel optimizer for queries containing a large number of joins, as well as set operators and aggregate functions. The platform for the execution is a shared-disk multiprocessor machine supporting bushy parallelism and pipeline processing. Our model partitions the query into almost independ...
以下示例将多个查询提示应用于 query_id 39,包括 RECOMPILE、MAXDOP 1 和 SQL 2012 查询优化器行为:SQL 复制 EXEC sys.sp_query_store_set_hints @query_id= 39, @query_hints = N'OPTION(RECOMPILE, MAXDOP 1, USE HINT(''QUERY_OPTIMIZER_COMPATIBILITY_LEVEL_110''))'; ...
OptimizerHintKind OptionState OptionValue OrderBulkInsertOption OrderByClause OrderIndexOption OutputClause OutputIntoClause OverClause PageVerifyDatabaseOption PageVerifyDatabaseOptionKind ParameterizationDatabaseOption ParameterizedDataTypeReference ParameterlessCall ...
JoinTableReference JsonForClause JsonForClauseOption JsonForClauseOptions JsonKeyValue KeyOption KeyOptionKind KeySourceKeyOption KeywordCasing KillQueryNotificationSubscriptionStatement KillStatement KillStatsJobStatement LabelStatement LedgerOption LedgerTableOption LedgerViewOption LeftFunctionCall LikePredicate Line...
When SQLPROP_SQLLIKE is on, the optimizer can send a query that contains a SQL Server LIKE predicate to the remote server, if doing this is justified by the query plan. If SQLPROP_SQLLIKE is off, a SQL Server LIKE predicate is always evaluated locally. SQLPROP_SUBQUERIES Specifies the ...
(0.00 sec) root@localhost : test 02:09:36>set session optimizer_switch='index_merge_intersection=off'; Query OK, 0 rows affected (0.00 sec) root@localhost : test 02:10:12>explain select * From idx_mer where name='e' and name1 = 'ee'\G; *** 1. row *** id: 1 select_type:...