（转）linux下启动oracle
原文地址：http://blog.sina.com.cn/s/blog_56d8ea900100noxa.html
启动数据库实例，分为两步：第一步，启动监听；第二步，启动数据库实例。

一、如何启动数据库实例
   1.进入到sqlplus启动实例
[oracle@redhat ~]$ su - oracle                                 --“切换到oracle用户”
Password:
[oracle@redhat ~]$ lsnrctl start                               --“打开监听”
LSNRCTL for Linux: Version 10.2.0.1.0 - Production on 14-OCT-2009 19:06:40
Copyright (c) 1991, 2005, Oracle.  All rights reserved.
Starting /home/oracle/product/10g/bin/tnslsnr: please wait...
TNSLSNR for Linux: Version 10.2.0.1.0 - Production
System parameter file is /home/oracle/product/10g/network/admin/listener.ora
Log messages written to /home/oracle/product/10g/network/log/listener.log
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC2)))
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=redhat)(PORT=1522)))
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC2)))
STATUS of the LISTENER
------------------------
Alias                     LISTENER
Version                   TNSLSNR for Linux: Version 10.2.0.1.0 - Production
Start Date                14-OCT-2009 19:06:40
Uptime                    0 days 0 hr. 0 min. 0 sec
Trace Level               off
Security                  ON: Local OS Authentication
SNMP                      OFF
Listener Parameter File   /home/oracle/product/10g/network/admin/listener.ora
Listener Log File         /home/oracle/product/10g/network/log/listener.log
Listening Endpoints Summary...
  (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC2)))
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=redhat)(PORT=1522)))
Services Summary...
Service "PLSExtProc" has 1 instance(s).
  Instance "PLSExtProc", status UNKNOWN, has 1 handler(s) for this service...
The command completed successfully
[oracle@redhat ~]$ sqlplus /nolog                                --“进入到sqlplus”
SQL*Plus: Release 10.2.0.1.0 - Production on Wed Oct 14 19:06:45 2009
Copyright (c) 1982, 2005, Oracle.  All rights reserved.
SQL> conn /as sysdba                                              --“连接到sysdba”
Connected to an idle instance.
SQL> startup                                                 &nbs