alter system set processes=500 scope=spfile;
alter system set sessions=500 scope=spfile;
（
select value from v$parameter where name = ‘processes‘;
或
show parameter processes;
查询数据库当前进程的连接数
select count(*) from v$process;
查询数据库当前进程的会话数
select count(*) from v$session;
重启数据库
SQL> shutdown immediate;
SQL> startup;
查看当前有哪些用户正在使用数据
select osuser,a.username,cpu_time/executions/1000000||‘s‘,sql_fulltext,machine
from v$session a,v$sqlarea b where a.sql_address = b.address order by cpu_time/executions desc;
参考地址：https://www.cnblogs.com/uumiss/p/4905482.html
原文：https://www.cnblogs.com/kiko2014551511/p/12868819.html