db2需要注意的问题

1. db2新建数据库为什么没写密码却可以输入密码连接

    因为新建数据库默认以系统名为数据库用户名，系统密码为自己的用户名密码

2. 报错信息：

    SQL0100W No row was found for FETCH, UPDATE or DELETE; or the result of a

    query is an empty table. SQLSTATE=02000

    DB20000I The SQL command completed successfully.

解决办法：带有SQL0100W的仅仅是一个警告，并不是报错，它只是告诉你没有结果返回给你，或者返回结果是个空表。

3. 经典例子：查找ESBTLOG表中msg_id，tran_date都相同的记录。

db2 "select msg_id, tran_date, count(*) from ESBTLOG order by msg_id, tran_date having count(*)>1"

4. 报错信息：

    DB21034E The command was processed as an SQL statement because it was not a

     valid Command Line Processor command. During SQL processing it returned:

     SQL0911N The current transaction has been rolled back because of a deadlock

     or timeout. Reason code "2". SQLSTATE=40001

    解决方法：db2 reorg table ESBTLOG(table name)

5. 表空间异常，状态码：0x0020

    解决方案：db2 backup db ixpdb tablespace USERSPACE1 online include logs(在当前目录下备份表空间)

    查看表空间：db2 list tablespaces show detail

6. 强行关闭数据库

    a. db2 connect reset

    b. 

        1). 查看是否有活动的连接

              命令：db2 list applications for db db_name

         2). 关闭连接

              命令：db2 force application all

    c. db2stop (db2stop force)