ORA-01506: missing or illegal database name，Oracle 啟動執行個體所需最小化參數

以下實驗過程來自10.2.0.3 
引用SQL> select * from v$version; 

BANNER 
---------------------------------------------------------------- 
Oracle Database 10g Enterprise Edition Release 10.2.0.3.0 - Prod 
PL/SQL Release 10.2.0.3.0 - Production 
CORE    10.2.0.3.0      Production 
TNS for Linux: Version 10.2.0.3.0 - Production 
NLSRTL Version 10.2.0.3.0 - Production

我們知道Oracle啟動執行個體尋找參數檔案的順序為spfile<sid>.ora,spfile.ora,init<sid>.ora。那麼Oracle啟動一個執行個體最小化參數是什麼呢？以下就是實驗過程。 
建立任意名字執行個體 
引用[ora10g@mcprod ~]$ export ORACLE_SID=zhoul

啟動執行個體需要參數檔案initzhoul.ora 
引用[ora10g@mcprod ~]$ sqlplus "/as sysdba" 

SQL*Plus: Release 10.2.0.3.0 - Production on Sat Jan 9 13:55:35 2010 

Copyright (c) 1982, 2006, Oracle.  All Rights Reserved. 

Connected to an idle instance. 

SQL> startup 
ORA-01078: failure in processing system parameters 
LRM-00109: could not open parameter file '/ora10g/oracle/product/10.2.0/db_1/dbs/initzhoul.ora' 
SQL> exit 
Disconnected

建立參數檔案initzhoul.ora 
引用[ora10g@mcprod ~]$ touch /ora10g/oracle/product/10.2.0/db_1/dbs/initzhoul.ora

再次嘗試啟動，提示需要參數db_name 
引用SQL> startup nomount 
ORA-01506: missing or illegal database name

添加db_name至參數檔案 
引用[ora10g@mcprod ~]$ echo "db_name=zhoul">initzhoul.ora

再次嘗試啟動zhoul執行個體，啟動成功 
引用SQL> startup nomount 
ORACLE instance started. 

Total System Global Area  117440512 bytes 
Fixed Size                  1260384 bytes 
Variable Size              58721440 bytes 
Database Buffers           50331648 bytes 
Redo Buffers                7127040 bytes

查看資料字典v$parameter,發現啟動該執行個體的只有db_name是非預設，也就是說只要只要設定參數db_name，即可啟動資料庫執行個體，其他參數均可採用初始值。 
引用SQL> select name from v$parameter where isdefault='FALSE'; 

NAME 
-------------------------------------------------------------------------------- 
db_name

觀察alert_zhoul.log，可以看到Oracle在啟動執行個體zhoul中調成了部分初始值。注意到undo retention自動調整被關閉。 
引用SQL> show parameter background_core_dump 

NAME                                 TYPE        VALUE 
------------------------------------ ----------- ------------------------------ 
background_core_dump                 string      partial 

[ora10g@mcprod log]$ cat  alert_zhoul.log 
Sat Jan  9 13:58:08 2010 
Adjusting the default value of parameter parallel_max_servers 
from 40 to 25 due to the value of parameter processes (40) 
Sat Jan  9 13:58:08 2010 
Starting ORACLE instance (normal) 
LICENSE_MAX_SESSION = 0 
LICENSE_SESSIONS_WARNING = 0 
Sat Jan  9 13:58:19 2010 
Adjusting the default value of parameter parallel_max_servers 
from 40 to 25 due to the value of parameter processes (40) 
Sat Jan  9 13:58:19 2010 
Starting ORACLE instance (normal) 
LICENSE_MAX_SESSION = 0 
LICENSE_SESSIONS_WARNING = 0 
Sat Jan  9 13:59:52 2010 
Adjusting the default value of parameter parallel_max_servers 
from 40 to 25 due to the value of parameter processes (40) 
Sat Jan  9 13:59:52 2010 
Starting ORACLE instance (normal) 
LICENSE_MAX_SESSION = 0 
LICENSE_SESSIONS_WARNING = 0 
Sat Jan  9 14:01:25 2010 
Adjusting the default value of parameter parallel_max_servers 
from 40 to 25 due to the value of parameter processes (40) 
Sat Jan  9 14:01:25 2010 
Starting ORACLE instance (normal) 
LICENSE_MAX_SESSION = 0 
LICENSE_SESSIONS_WARNING = 0 
Shared memory segment for instance monitoring created 
Picked latch-free SCN scheme 2 
Using LOG_ARCHIVE_DEST_1 parameter default value as /ora10g/oracle/product/10.2.0/db_1/dbs/arch 
Autotune of undo retention is turned off. 
LICENSE_MAX_USERS = 0 
SYS auditing is disabled 
ksdpec: called for event 13740 prior to event group initialization 
Starting up ORACLE RDBMS Version: 10.2.0.3.0. 
System parameters with non-default values: 
  db_name                  = zhoul 
PMON started with pid=2, OS id=32133 
PSP0 started with pid=3, OS id=32135 
MMAN started with pid=4, OS id=32137 
DBW0 started with pid=5, OS id=32139 
LGWR started with pid=6, OS id=32141 
CKPT started with pid=7, OS id=32143 
SMON started with pid=8, OS id=32145 
RECO started with pid=9, OS id=32147 
MMON started with pid=10, OS id=32149 
MMNL started with pid=11, OS id=32151原文連結：http://dbzone.iteye.com/blog/566478