SQL子查询
1. 包含在select子句中的子查询:SQL> select dname,(select max(sal) from emp where deptno=dept.deptno) max_sal2 from dept3 /DNAME MAX_SAL-------------- ----------ACCOUNTING 5000RESEARCH 3000SALES 2850OP...
redhat的etc目录
1. /etc/sysconfig目录包含由rethat配置的多个脚本文件,以区别于etc目录下那些不是由redhat设计的配置文件。2. /etc/motd,表示Message Of Today ,文件的内容为所有用户登录系统时显示的欢迎信息,管理员可以根据...
Oracle中的checkpoint进程
The checkpoint (CKPT) process is charged with telling the database writer process when to writethe dirty data in the memory buffers to disk. After telling the database writer process to write thechang...
WHY TABLESPACES?
WHY TABLESPACES?Tablespaces perform a number of key functions in an Oracle database, but the concept of a tablespace is not commonto all relational databases. For instance, the Microsoft SQL Server da...
Jim Gray:数据管理历史
Data Management: Past, Present, and Futurehttp://arxiv.org/ftp/cs/papers/0701/0701156.pdf
关于Oracle游标的简单定义
An Oracle cursor is a handle to an area in memory that holds the result set of a SQL query, enabling you to individually process the rows in the result set. Oracle uses implicit cursors for all DML st...
基于Linux的数据库管理与维护--实验1:Linux常用客户端工具及常用命令
1. 下载PuTTY(一般不需要安装即可直接使用),以root用户使用PuTTY与虚拟机中的Linux连接成功,并执行几个简单的命令。以下操作均在PuTTY中执行。2. 复习讲义或笔记中正则表达式的用法3. 用vi输入下面一段英文(如果要...
更改solaris主机名及ip地址(zt)
更改solaris IP地址和主机名 一 、更改solaris IP 地址 立即更改: #ifconfig hme0 inet 192.168.1.1 netmask 255.255.255.0 up (重起之后新的ip将会丢失) 永久更改: 1)编辑文件/etc/hosts,更改...
数据库原理与应用----实验1:Oracle基本操作
1. 启动、关闭数据库服务,然后分别以sys及system用户,用SQL*Plus连接数据库,查看是否可以正常连接数据库,如果不能连接数据库,记下出现的错误。 启动服务:C:> net start oracleservicelawl...
使用man ascii查看ascii码表
[root@redhat ~]# man ascii
用perl代替grep
[root@redhat ~]# cat lawHi, David,I think I failed my anatomy test yeserday. I had a terriblestomachache. I think I ategreen tom too many fried green tomatoes.Anyway, Tom, I need your help. I'd like t...
一些第三方oracle工具
TOAD (Tool for Oracle Application Developers) http://www.quest.com/toad ,The most popular of all the PL/SQL IDEs, TOAD is famous for its tabbed browser and "Swiss Army Knife" approach. Available in b...
使用汉语环境时,grep命令竟然不区分大小写
[root@redhat ~]# export LANG=zh_CN.GB18030[root@redhat ~]# grep [A-Z]om lawAnyway, Tom, I need your help. I'd like to make the test upthink you could help me? After work, about 7 PM,come to[root@redha...
distinct与order by结合使用时要注意
SQL-99中,在select中使用distinct关键字后,在order by中出现的字段名称不能超过select子句的范围,如:SQL> select distinct ename,sal from emp order by deptno;select distinct ename,sal from emp order by de...
order by在SQL Server与Oracle中的一个区别
在SQL Server中,子查询如果使用order by,则报错:1> select * from (select au_fname from authors) as d2> goau_fname--------------------AbrahamReginaldCheryl1> select * from (select au_fname from authors...
google可以搜索电子图书了
http://books.google.com
Top DBA Shell Scripts for Monitoring the Database
Top DBA Shell Scripts
Burleson的Oracle技术支持报价
Donald K. Burleson Consulting PricesThe following Oracle consulting rates are for personal consulting and expert witness testimony by Donald Burleson. With more than two decades of Oracle c...
转贴oracle两篇文章:Guide to Advanced Linux Command Mastery
Guide to Advanced Linux Command Mastery, Part 1Guide to Advanced Linux Command Mastery, Part 2
top的用法
topThe top command is probably the most useful one for an Oracle DBA managing a database on Linux. Say the system is slow and you want to find out who is gobbling up all the CPU and/or memory. To disp...