session max

--1、主机执行
netstat -an| grep 1521 | wc -l 
--找到异常
--2、plsql执行
select t.INST_ID, t.PREV_SQL_ID,count(*) from gv$session t where t.STATUS='ACTIVE' group by t.INST_ID, t.PREV_SQL_ID order by t.INST_ID;
--异常SQL 
select *from v$sql t where t.SQL_ID='9ngq09yhhc1qf'; --sql_id 
--3、监听日志 lsnrctl status
/oracle/grid/diag/tnslsnr/nfzcdb01/listener/alert/log.xml
--AWR
sqlplus / as sysdba
SQL> @?/rdbms/admin/awrrpt.sql
--4、trc文件路径查看
show parameter dump



select *from v$sql t where t.SQL_ID='9ngq09yhhc1qf';

select * from v$active_session_history where 

select t.INST_ID, t.PREV_SQL_ID,count(*) from gv$session t where t.STATUS='ACTIVE' group by t.INST_ID, t.PREV_SQL_ID order by t.INST_ID;

select t.INST_ID, t.SQL_EXEC_ID,count(*) from gv$session t where t.STATUS='ACTIVE' group by t.INST_ID, t.SQL_EXEC_ID order by t.INST_ID;

select * from dba_hist_active_sess_history t order by t.sample_time desc;

select * from dba_hist_active_sess_history t where to_char(t.sql_exec_start,'yyyymmddHH24')='2018122910';

select t.sql_id,count(*) from dba_hist_active_sess_history t where to_char(t.sql_exec_start,'yyyymmddHH24')='2018122910' group by t.sql_id;

select t.machine,count(*) from dba_hist_active_sess_history t where to_char(t.sql_exec_start,'yyyymmddHH24')='2018122910' group by t.machine;

select to_char(sysdate,'yyyymmddHH24') from dual; 

select * from dba_jobs;