ORA-00020

Oracle8.1.6系统出现一个ORA-00020的小错误：

Microsoft Windows [版本 5.2.3790]
(C) 版权所有 1985-2003 Microsoft Corp.

 

C:\Documents and Settings\Administrator>d:

 

D:\>cd D:\oracle816\ora81\BIN

 

D:\oracle816\ora81\BIN>sqlplus /nolog

 

SQL*Plus: Release 8.1.6.0.0 - Production on 星期二 4月 29 14:30:49 2008

 

(c) Copyright 1999 Oracle Corporation.  All rights reserved.

 

SQL> conn as sysdba
ERROR：
ORA-00020: maximum number of processes (50) exceeded

 

SQL>

 

Parameter type	Integer
Default value	Derived from PARALLEL_MAX_SERVERS
Parameter class	Static
Range of values	6 to operating system-dependent
Real Application Clusters	Multiple instances can have different values.

specifies the maximum number of operating system user processes that can simultaneously connect to Oracle. Its value should allow for all background processes such as locks, job queue processes, and parallel execution processes.

The default values of the SESSIONS and TRANSACTIONS parameters are derived from this parameter. Therefore, if you change the value of PROCESSES, you should evaluate whether to adjust the values of those derived parameters.

关闭一些会话后，就可以登录了。我们看一下系统中的这两个参数“SESSIONS”和“TRANSACTIONS”的设置：

SQL> conn sys/change_on_install@qmyb as sysdba
已连接。
SQL> show parameter processes

 

NAME                                 TYPE    VALUE
------------------------------------ ------- ------------------------------
aq_tm_processes                      integer 0
db_writer_processes                  integer 1
job_queue_processes                  integer 0
log_archive_max_processes            integer 1
processes                            integer 50
SQL> show parameter sessions

 

NAME                                 TYPE    VALUE
------------------------------------ ------- ------------------------------
java_max_sessionspace_size           integer 0
java_soft_sessionspace_limit         integer 0
license_max_sessions                 integer 0
license_sessions_warning             integer 0
mts_sessions                         integer 0
sessions                             integer 60
SQL> show parameter transactions

 

NAME                                 TYPE    VALUE
------------------------------------ ------- ------------------------------
distributed_transactions             integer 500
transactions                         integer 66
transactions_per_rollback_segment    integer 5

SQL>

 

修改PFILE中的初始化参数process的值为150，然后重启数据库：

SQL> shutdown immediate
数据库已经关闭。
已经卸载数据库。
ORACLE 例程已经关闭。
SQL> startup
ORACLE 例程已经启动。

 

Total System Global Area 1177965836 bytes
Fixed Size                    70924 bytes
Variable Size             309727232 bytes
Database Buffers          868089856 bytes
Redo Buffers                  77824 bytes
数据库装载完毕。
数据库已经打开。

 

SQL>

这时再看这三个参数，发现sessions和transactions都自动调整了：

SQL> show parameter processes

 

NAME                                 TYPE    VALUE
------------------------------------ ------- ------------------------------
aq_tm_processes                      integer 0
db_writer_processes                  integer 1
job_queue_processes                  integer 0
log_archive_max_processes            integer 1
processes                            integer 150
SQL> show parameter sessions

 

NAME                                 TYPE    VALUE
------------------------------------ ------- ------------------------------
java_max_sessionspace_size           integer 0
java_soft_sessionspace_limit         integer 0
license_max_sessions                 integer 0
license_sessions_warning             integer 0
mts_sessions                         integer 0
sessions                             integer 170
SQL> show parameter transactions

 

NAME                                 TYPE    VALUE
------------------------------------ ------- ------------------------------
distributed_transactions             integer 500
transactions                         integer 187
transactions_per_rollback_segment    integer 5
SQL>

 

这个系统的版本是oracle8.1.6：

SQL> select * from v$version;

 

BANNER
----------------------------------------------------------------
Oracle8i Release 8.1.6.0.0 - Production
PL/SQL Release 8.1.6.0.0 - Production
CORE    8.1.6.0.0       Production
TNS for 32-bit Windows: Version 8.1.6.0.0 - Production
NLSRTL Version 3.4.1.0.0 - Production

 

SQL>