Before beginning this tutorial, you should be familiar with the concept of a SQL access plan.
在开始学习本教程之前,您应该熟悉SQL访问计划(access plan)的概念。
Before beginning this tutorial, you should be familiar with the concept of an SQL access plan.
在开始本教程之前,您应该熟悉SQL访问计划的概念。
One key advantage of pureQuery over SQLJ is the ease of enabling static SQL access in a way that is more streamlined.
pureQuery相对于 SQLJ的一个主要优点是很容易以更加简化的方式实现静态SQL访问。
Lastly, it provides direct SQL access to JDBC sources, though you should avoid these tags if you're trying to separate the UI and logic.
最后,它还提供了对jdbc源的SQL访问功能,不过如果您试图将UI和业务逻辑分隔开,就应该避免使用这些标签。
If some of the top SQL statements are considered unexpectedly expensive, further action is required to analyze the SQL access plan to see if anything can be improved.
如果其中一些最优sql语句被认为是异常昂贵的,下一步将需要分析SQL访问计划,看看是否还可以改进。
Relational databases provide the capability for the SQL statements to access information from more than one table through a joining of multiple tables.
关系数据库为sql语句提供了从一个以上的表中访问信息的能力,这是通过连接多个表来完成的。
However, application logic still needs to encode the details of SQL and access protocol.
然而,应用程序逻辑仍然需要编码SQL和访问协议的详细信息。
The implementation contains methods encapsulating all required SQL statements for data access and manipulation.
该实现包含封装所有用于数据访问和操纵的sql语句的方法。
As the previous section described, parameter marker usage in SQL statements fosters access plan reuse.
如上节所述,sql语句中的参数标记使用可促进访问计划重用。
Whether used together with access to SQL tables or used separately, this can greatly simplify application development.
无论是与对sql表的访问一起使用,还是单独使用,这都可以大大简化应用程序开发。
For simplicity, this article refers to a particular way of satisfying an SQL statement as the access path.
为简单起见,本文引用了一种满足sql语句的流行方法作为访问路径。
Remember that DB2 can only reuse an access plan if SQL statement texts completely match.
还记得吗,DB2仅在SQL语句文本完全匹配时才能重用访问计划。
As just described, if you can't find a DB2 equivalent function, you can rewrite your SQL to access data a different way.
根据以上所述,如果找不到DB 2中具有相同功能的函数,那么可以重写SQL,以不同的方式访问数据。
The access plan for a given SQL statement is generated at bind time.
一个特定sql语句的存取计划是在绑定时生成的。
For example, a federated query might be written in SQL and might specify access to product information.
例如,可以使用SQL编写联合查询,并可以指定对产品信息的访问。
When you write SQL statements that access DB2 data, be sure to follow these three guidelines for coding SQL for performance.
当您编写访问DB2数据的sql语句时,要确保遵循以下三个编码sQL的准则以获得最佳性能。
IBM I customers, worldwide, are now using SQL to define and access data.
如今,全世界IBMi客户都在使用SQL定义和访问数据。
If the cost estimatd does not correctly describe the real cost during SQL execution, the access plan picked by the optimizer may not be optimal.
如果评估得到的开销不能够正确反映SQL执行中的实际开销,那么优化器所选择的存取计划可能不是最优的。
The SQL explain facility provides detailed information about the access plan that the query optimizer chooses for an SQL statement.
SQL解释工具提供查询优化器为 SQL语句所选择的访问计划的有关详细信息。
SQLJ provides the unique ability to develop using static SQL statements and control access at the DB2 package level.
SQLJ提供了独特的使用静态SQL语句进行开发以及在DB2包级别控制访问的能力。
The SQL statement itself also impacts the access path selection.
sql语句本身也会影响访问路径选择。
SQL commands to perform database access.
执行数据库访问的SQL命令。
Placing the pieces on separate I/O paths reduces the contention of SQL operations that need to access the NPI.
将这些块放在不同的I/O路径中,可以减少访问NPI 所需的SQL操作的争用。
A simple program architecture would naturally mix the business logic with data access logic (like SQL).
简单的程序体系结构会自然地将业务逻辑和数据访问逻辑(如sql)混合。
You can use your database runtime client to process SQL statements that directly access the AUDIT_LOG_B view.
您可以在您的数据运行时客户端中直接使用SQL语句来直接访问 AUDIT_LOG_B视图。
Ensure that the proper SQL services are running on the SQL server to allow remote access to the SQL instance.
确认在SQL服务器上运行了合适的SQL服务以支持对SQL实例的远程访问。
For instance, you may rarely, if ever, be required to analyze the access plans for SQL statements.
例如,您可能很少被要求分析sql语句的访问计划。
Indexes that will provide index-only access for the SQL statement.
为sql语句提供进索引访问的索引。
SQL procedures are written entirely in SQL and allow access to DB2 resources via SQL operations.
SQL过程是完全用 SQL编写的,可以通过 SQL操作访问DB2资源。
The dashed boxes in Figure 1 (SQL model and Database access model) indicate temporary models created from the abstract model.
图1中的虚线框(SQL模型和数据库访问模型)表示从抽象模型创建的临时模型。
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