The query compiler performs two major categories of rewrite
查询编译器主要可以执行两种类型的重写
The query compiler uses these characteristics and restrictions when planning the query.
当计划查询时,查询编译器使用这些特征和约束。
When the query is submitted, its syntax and semantics are analyzed by the query compiler.
当提交该查询时,查询编译器会分析它的语法和语义。
If indexes are created on the CGTT table, the query compiler will take those indexes into account.
如果为cgtt表创建了索引,则查询编译器会将这些索引考虑在内。
The SQL statements and commands submitted in a pass-through session do not go through the federated query compiler.
在pass - through会话中提交的sql语句和命令不会通过联邦查询编译器。
The federated query compiler makes a cost-based decision and makes the process of using MQTs transparent to the users.
联邦查询编译器作出一个基于成本的决策,并使得使用MQT的过程对用户是透明的。
The query compiler expands view definitions into the main statement block, which might result in a more complex statement.
查询编译器将视图定义展开成主语句块,从而产生一个更复杂的语句。
The query compiler uses this information while checking any character comparison operations, to decide how to evaluate the operations.
查询编译器在检查字符比较操作时使用该信息,以决定如何执行操作。
To process the query, the DB2 query compiler consults information in the DB2 federated database system catalog and the data source wrapper modules.
为了处理该查询,DB 2查询编译器查阅DB 2联邦数据库系统编目中的信息以及数据源包装器模块中的信息。
Other problems in the optimizer or query compiler area, such as SQL0901N errors or instance crashes, can also be recreated using the methods explained in this article.
优化器或查询编译器领域中的其他问题,例如SQL 0901n错误或实例崩溃,也可以使用本文中所解释的方法来重新创建。
The SQL compiler uses informational constraints to improve query performance.
SQL编译器使用信息约束来提高查询性能。
After the query is submitted to the SQL compiler, the semantics phase expands the view definition and merges it into the original query as shown below.
把该查询提交给SQL编译器之后,语义阶段展开视图定义,并将它合并到初始的查询中,如下所示。
The SQL compiler USES query optimization to select the best performing access path for any given SQL statement (within a reasonable amount of time, of course).
SQL编译器使用查询优化来为任何给定的sql语句选择表现最好的访问路径(当然,这要在合理的时间内)。
If you want to disable the usage of the constraints by the SQL compiler, you can use the disable QUERY OPTIMIZATION clause. For example.
如果您想通过编译器禁用约束,那么可以使用DISABLEQUERYoptimization子句。
Query expressions are based on compiler translations of patterns; you don't need to implement any more of the pattern than the relevant query expression requires
查询表达式基于编译器的模式转换,除了相关查询表达式需要的模式之外,你不必实现其它的;
The existence of many candidate MQTs might prevent the compiler from choosing the best MQT for that query.
许多备选MQT的存在可能会防止编译器为该查询选择最好的MQT。
After the optimizer has done its work, the compiler converts the query plan into executable code segments called snippets.
优化器完成工作后,编译器将把查询计划转换为可执行的代码段,称为snippet。
The variables in a query expression are all strongly typed, although in many cases you do not have to provide the type explicitly because the compiler can infer it.
查询表达式中的变量都是强类型的,但许多情况下您不需要显式提供类型,因为编译器可以推断类型。
According to the processing procedure of query pre-compiler, this paper givens the general design and implementation of syntax analysis, semantics analysis in MDBI query pre-compiler.
按照查询预处理的处理过程,分别描述了MDBI查询预处理器中词法分析、语法分析、语义分析的设计和实现。
According to the processing procedure of query pre-compiler, this paper givens the general design and implementation of syntax analysis, semantics analysis in MDBI query pre-compiler.
按照查询预处理的处理过程,分别描述了MDBI查询预处理器中词法分析、语法分析、语义分析的设计和实现。
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