Oracle创建实例的最少参数需求
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 2006
copyright (c) 1982, 2002, oracle corporation. all rights reserved.
connected to an idle instance.
sql> startup nomount;
ora-01078: failure in processing system parameters
lrm-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.ora
sql> startup nomount;
oracle instance started.
total system global area 97588504 bytes
fixed size 451864 bytes
variable size 46137344 bytes
database buffers 50331648 bytes
redo 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.log
mon may 8 11:09:04 2006
starting oracle instance (normal)
mon may 8 11:09:04 2006
warning: einval creating segment of size 0x0000000006400000
fix shm parameters in /etc/system or equivalent
license_max_session = 0
license_sessions_warning = 0
scn scheme 2
using log_archive_dest parameter default value
license_max_users = 0
sys auditing is disabled
starting up oracle rdbms version: 9.2.0.4.0.
system parameters with non-default values:
db_name = julia
pmon started with pid=2
dbw0 started with pid=3
lgwr started with pid=4
ckpt started with pid=5
smon started with pid=6
reco started with pid=7