db2 with写法在DB2 中,WITH 子句可以用于创建公共表表达式(CTE),这些表达式可以在主 查询中重复使用,以提高查询的可读性和性能。以下是一个使用 WITH 子句的示例: sql 复制代码 WITH cte_example AS ( SELECT column1, column2 FROM table1 WHERE condition ) SELECT * FROM cte_example WHERE column1 = '...
In Sybase we frequently use temp. tables and stored procedure when we need to get a result from many tables. For example, DB2 中的临时表可以一个SQL表示(当然这只是一种,你可以创建session的临时表): with query1 ( col1, col2, col3, ..., colN) as ( select ... ), query2 (col, .....
example 4: define the table function from example 4 with auditing. create function deptemployees (deptno char(3)) returns table (empno char(6), lastname varchar(15), firstname varchar(12)) language sql modifies sql data no external action deterministic begin atomic insert into audit values (u...
Description procedure-name Names the procedure being defined. It is a qualified or unqualified name that designates a procedure. The unqualified form of procedure-name is an SQL identifier (with a maximum length of 128). In dynamic SQL statements, the CURRENT SCHEMA special register is used as ...
example 4: define the table function from example 4 with auditing. create function deptemployees (deptno char(3)) returns table (empno char(6), lastname varchar(15), firstname varchar(12)) language sql modifies sql data no external action ...
sql语句。 可选项 ? [phrase | message | sqlstate | class-code] ,? 后可以跟 phrase | message | sqlstate | class-code。 有人可能会问了,你怎么知道 "{} 里的内容表示必选项,必须有", -a, -c, -d 那些选项都是啥意思呢?答案:第一: 如果你看不懂这些帮助信息,请看上述输入信息的倒数第四行...
example 4: define the table function from example 4 with auditing. 1. create function deptemployees (deptno char(3)) returns table (empno char(6), lastname varchar(15), firstname varchar(12)) language sql modifies sql data no external action ...
Example: db2advis -d test_db -a user/password -i D:\temp\sql_2.txt > D:\temp\sql_2_result_db2advis.txt 1. db2数据库中通常出现消耗时间成本很高的sql语句,耗时长的sql语句会长时间占用各种资源,如CPU, Memory, 事务日志等,增加其他sql语句的等待时间,导致整个数据库性能变差。因此我们会时刻监控性...
DB2®设计顾问程序可分析 SQL 语句以提供有关如何提高数据库性能的建议。可使用程序包高速缓存中的语句(包括由程序包高速缓存事件监视器捕获的语句)作为设计顾问程序的输入,从而确定对于某个给定工作负载(甚至是在两个时间点内运行的所有语句)可进行哪些更改来提高性能。
For example, a loss of precision can occur when an XML integer value is cast to the SQL data type DECFLOAT. If the cast causes a loss of precision, the result will be rounded to the approximate value when it is stored in the index. The cast result cannot be outside of the range ...