第一步,在cmd命令行,输入sqlplus
第二步,根据提示输入用户名与密码
1. 查看processes和sessions参数
SQL> show parameter processes
NAME????????????????????????????????? TYPE???????? VALUE
db_writer_processes????????????????? integer???? 1
gcs_server_processes???????????????? integer???? 0
job_queue_processes????????????????? integer???? 10
log_archive_max_processes??????????? integer???? 2
processes??????????????????????????? integer???? 50
SQL> show parameter sessions
NAME????????????????????????????????? TYPE???????? VALUE
license_max_sessions???????????????? integer???? 0
license_sessions_warning???????????? integer???? 0
logmnr_max_persistent_sessions?????? integer???? 1
sessions???????????????????????????? integer???? 60
shared_server_sessions?????????????? integer
2. 修改processes和sessions值
SQL> alter system set processes=300 scope=spfile;
系统已更改。
SQL> alter system set sessions=335 scope=spfile;
系统已更改。
3. 修改processes和sessions值必须重启oracle服务器才能生效
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;