数据库连接池

select count(*) from v$process;
--3622
select value from v$parameter where name = 'processes';

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

select username,a.* from v$session a where username is not null order by a.sid desc;

select sid,serial#,username,status,a. from v$session a;

select osuser,count(osuser) from v$session where username is not null group by osuser;