A recent enhancement to DB2 for I 6.1 makes it possible to understand the optimizer use at the SQL statement level within the SQL Performance Monitor.
DB 2 for i 6.1最近的一个增强使得理解在SQL性能监视器中sql语句级使用优化器成为可能。
ISOLATION level is set at the session level using set ISOLATION, set at the SQL statement level using the WITH clause or set at the database level using a database Configuration parameter.
使用SET ISOLATION在会话级、使用with子句在sql语句级或使用数据库配置参数在数据库级设置隔离级别。
Although different access paths for the same SQL statement produce the same result set, they most likely do not perform the task with the same level of performance.
虽然相同sql语句的不同访问路径会产生相同的结果集,但是它们很有可能不会通过同样的性能级别来执行任务。
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