数据库运行监视

--查看SGA统计信息:
select * from v$sgastat order by nvl(pool, 1), bytes desc;

--查看排序情况:
select a.value memory,
       b.value disk,
       trunc(1 - b.value / a.value) * 100 ratio
  from v$sysstat a, v$sysstat b
 where a.name = 'sorts (memory)'
   and b.name = 'sorts (disk)';
   
--查看日志切换情况:
select *
  from (select * from v$log_history order by first_time desc)
 where rownum < 100;
 
--查看锁资源:
select b.session_id,
       b.oracle_username,
       b.os_user_name,
       b.process,
       b.locked_mode,
       a.owner,
       a.object_name,
       a.object_id,
       a.object_type,
       b.xidusn,
       b.xidslot,
       b.xidsqn
  from all_objects a, v$locked_object b
 where a.object_id = b.object_id;
 
--查看库缓存命中率:
select namespace,
       gets,
       gethits,
       trunc(gethitratio * 100, 2) gethitratio,
       pins,
       pinhits,
       trunc(pinhitratio * 100, 2) pinhitratio,
       reloads,
       invalidations,
       dlm_lock_requests,
       dlm_pin_requests,
       dlm_pin_releases,
       dlm_invalidation_requests,
       dlm_invalidations
  from v$librarycache;
  
--查看数据缓存命中率:
select a.*, trunc((1 - phys / (gets + con_gets)) * 100, 2) "HIT RATIO"
  from (select sum(decode(name, 'physical reads', value, 0)) phys,
               sum(decode(name, 'db block gets', value, 0)) gets,
               sum(decode(name, 'consistent gets', value, 0)) con_gets
          from v$sysstat
       ) a ;

--查看WorkArea情况:
select name, value from v$sysstat where name like '%workarea%';

--查看当前会话等待事件:
select * from v$session_wait;

--查看数据库大小:
select '合计' OWNER, trunc(sum(bytes) / 1024 / 1024) "Size (M)"
  from dba_segments
union all
select owner, trunc(sum(bytes) / 1024 / 1024) "Size (M)"
  from dba_segments
 group by owner;
 
--查看等待事件的统计信息:
Select event, total_waits, time_waited, average_wait
  from v$system_event
 order by total_waits desc;