oracle修改最大并发数

SQL> show parameter processes;

 

NAME     TYPE VALUE

------------------------------------ ----------- ------------------------------

aq_tm_processes     integer 0

db_writer_processes     integer 2

gcs_server_processes     integer 0

global_txn_processes     integer 1

job_queue_processes     integer 0

log_archive_max_processes     integer 5

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

sessions     integer 256

shared_server_sessions     integer

SQL> alter system set processes = 300 scope = spfile;

 

System altered.

 

SQL> alter system set processes = 1000 scope = spfile;

 

System altered.

 

SQL> alter system set sessions=1100  scope=spfile;

 

System altered.

 

SQL> shutdown immshutdown immediate;

SP2-0717: illegal SHUTDOWN option

SQL> 

SQL> 

SQL> shutdown immediate;

Database closed.

Database dismounted.

ORACLE instance shut down.

SQL> startup

ORACLE instance started.

 

Total System Global Area 1.3429E+10 bytes

Fixed Size    2217992 bytes

Variable Size 8589936632 bytes

Database Buffers 4831838208 bytes

Redo Buffers    4661248 bytes

Database mounted.

Database opened.

SQL> 

 

 

ORACLE的连接数(sessions)与其参数文件中的进程数(process)有关，它们的关系如下：

sessions=(1.1*process+5)

摘（二）

查询数据库当前进程的连接数：

select count(*) from v$process;

查看数据库当前会话的连接数：

elect count(*) from v$session;

查看数据库的并发连接数：

select count(*) from v$session where status='ACTIVE';

查看当前数据库建立的会话情况：

select sid,serial#,username,program,machine,status from v$session;

查询数据库允许的最大连接数：

select value from v$parameter where name = 'processes';

或者：show parameter processes;

修改数据库允许的最大连接数：

alter system set processes = 300 scope = spfile;

(需要重启数据库才能实现连接数的修改)

重启数据库：

shutdown immediate;

startup;

查看当前有哪些用户正在使用数据：

select osuser,a.username,cpu_time/executions/1000000||'s',sql_fulltext,machine

from v$session a,v$sqlarea b

where a.sql_address = b.address

order by cpu_time/executions desc;

备注：UNIX 1个用户session对应一个操作系统process，而Windows体现在线程。

启动oracle

su - oracle

sqlplus system/pwd as sysdba   //进入sql

startup                                      //启动数据库

lsnrctl start                               //启动监听

sqlplus "/as sysdba"

shutdown immediate;

startup mount;

 

alter database open;