详细讲解如何用Oracle创建实例的参数需求

我们知道,Oracle在启动过程中,需要读取参数文件(pfile/spfile)来创建实例.Oracle在启动过程中,寻找参数文件的顺序为:

spfile<sid>.ora,spfile.ora,init<sid>.ora.

而创建实例的过程中,Oracle需要的最少参数为一个,即db_name参数.

我们来看一个测试,启动一个任意设置的实例,本例ORACLE_SID=julia:

oracle@jumper dbs]$ export ORACLE_SID=julia[oracle@jumper dbs]$ sqlplus '/ as sysdba'SQL*Plus: Release 9.2.0.4.0 - Production on Mon May 8 11:08:36 2006Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved.Connected to an idle instance.SQL> startup nomount;ORA-01078: failure in processing system parametersLRM-00109: could not open parameter file '/opt/oracle/product/9.2.0/dbs/initjulia.ora'

Oracle最后检查的文件为initjulia.ora,让我们创建这个文件,然后数据库实例即可创建:

SQL> ! echo 'db_name=julia' > /opt/oracle/product/9.2.0/dbs/initjulia.oraSQL> startup nomount;ORACLE instance started.Total System Global Area 97588504 bytesFixed Size 451864 bytesVariable Size 46137344 bytesDatabase Buffers 50331648 bytesRedo Buffers 667648 bytes

我们可以看一下缺省的各类文件的存储地点:

SQL> show parameter dump_dest NAME TYPE VALUE --------------- ----------------- -------- background_dump_dest string ?/rdbms/log core_dump_dest string ?/dbs user_dump_dest string ?/rdbms/log SQL> show parameter control_files NAME TYPE VALUE --------------- -----------------control_files string ?/dbs/cntrl@.dbf

我们顺便看一下缺省的,警报日志中记录的信息:

oracle@jumper dbs]$ cat $ORACLE_HOME/rdbms/log/alert_julia.logMon May 8 11:09:04 2006Starting ORACLE instance (normal)Mon May 8 11:09:04 2006WARNING: EINVAL creating segment of size 0x0000000006400000fix shm parameters in /etc/system or equivalentLICENSE_MAX_SESSION = 0LICENSE_SESSIONS_WARNING = 0SCN scheme 2Using log_archive_dest parameter default valueLICENSE_MAX_USERS = 0SYS auditing is disabledStarting up ORACLE RDBMS Version: 9.2.0.4.0.System parameters with non-default values: db_name= juliaPMON started with pid=2DBW0 started with pid=3LGWR started with pid=4CKPT started with pid=5SMON started with pid=6RECO started with pid=7