Oracle 常用DBA SQL

Oracle查询表空间使用情况
　--查询表空间使用情况
　　SELECT UPPER(F.TABLESPACE_NAME) "表空间名",
　　D.TOT_GROOTTE_MB "表空间大小(M)",
　　D.TOT_GROOTTE_MB - F.TOTAL_BYTES "已使用空间(M)",
　　TO_CHAR(ROUND((D.TOT_GROOTTE_MB - F.TOTAL_BYTES) / D.TOT_GROOTTE_MB * 100,2),'990.99') || '%' "使用比",
　　F.TOTAL_BYTES "空闲空间(M)",
　　F.MAX_BYTES "最大块(M)"
　　FROM (SELECT TABLESPACE_NAME,
　　ROUND(SUM(BYTES) / (1024 * 1024), 2) TOTAL_BYTES,
　　ROUND(MAX(BYTES) / (1024 * 1024), 2) MAX_BYTES
　　FROM SYS.DBA_FREE_SPACE
　　GROUP BY TABLESPACE_NAME) F,
　　(SELECT DD.TABLESPACE_NAME,
　　 ROUND(SUM(DD.BYTES) / (1024 * 1024), 2) TOT_GROOTTE_MB
　　FROM SYS.DBA_DATA_FILES DD
　　GROUP BY DD.TABLESPACE_NAME) D
　　WHERE D.TABLESPACE_NAME = F.TABLESPACE_NAME
　　ORDER BY 1;
　　--查询表空间的free space
　　select tablespace_name,
　　count(*) as extends,
　　round(sum(bytes) / 1024 / 1024, 2) as MB,
　　sum(blocks) as blocks
　　from dba_free_space
　　group by tablespace_name;

　　--查询表空间的总容量
　　select tablespace_name, sum(bytes) / 1024 / 1024 as MB
　　from dba_data_files
　　group by tablespace_name;

　　--查询表空间使用率
　　select total.tablespace_name,
　　round(total.MB, 2) as Total_MB,考试大论坛
　　round(total.MB - free.MB, 2) as Used_MB,
　　round((1 - free.MB / total.MB) * 100, 2) || '%' as Used_Pct
　　from (select tablespace_name, sum(bytes) / 1024 / 1024 as MB
　　from dba_free_space
　　group by tablespace_name) free,
　　(select tablespace_name, sum(bytes) / 1024 / 1024 as MB
　　from dba_data_files
　　group by tablespace_name) total
　　where free.tablespace_name = total.tablespace_name;


1.查找当前表级锁的SQL如下：
select sess.sid,
    sess.serial#,
    lo.oracle_username,
    lo.os_user_name,
    ao.object_name,
    lo.locked_mode
    from v$locked_object lo,
    dba_objects ao,
    v$session sess
where ao.object_id = lo.object_id and lo.session_id = sess.sid;

2.杀掉锁表进程：
alter system kill session '436,35123';

3.RAC环境中锁查找：
SELECT inst_id,DECODE(request,0,'Holder: ','Waiter: ')||sid sess,
        id1, id2, lmode, request, type,block,ctime
FROM GV$LOCK
WHERE (id1, id2, type) IN
       (SELECT id1, id2, type FROM GV$LOCK WHERE request>0)
ORDER BY id1, request;
 


4.监控当前数据库谁在运行什么SQL语句
select osuser, username, sql_text 
from  v$session a, v$sqltext b
where  a.sql_address =b.address order by address, piece;



5.找使用CPU多的用户session
select a.sid,spid,status,substr(a.program,1,40) prog, a.terminal,osuser,value/60/100 value
from  v$session a,v$process b,v$sesstat c
where  c.statistic#=12 and 
       c.sid=a.sid and 
       a.paddr=b.addr 
       order by value desc;


6.查看死锁信息
SELECT (SELECT username
          FROM v$session
         WHERE SID = a.SID) blocker, a.SID, 'is blocking',
       (SELECT username
          FROM v$session
         WHERE SID = b.SID) blockee, b.SID
  FROM v$lock a, v$lock b
WHERE a.BLOCK = 1 AND b.request > 0 AND a.id1 = b.id1 AND a.id2 = b.id2;


7.具有最高等待的对象
SELECT   o.OWNER,o.object_name, o.object_type, a.event,
         SUM (a.wait_time + a.time_waited) total_wait_time
    FROM v$active_session_history a, dba_objects o
   WHERE a.sample_time BETWEEN SYSDATE - 30 / 2880 AND SYSDATE
     AND a.current_obj# = o.object_id
GROUP BY o.OWNER,o.object_name, o.object_type, a.event
ORDER BY total_wait_time DESC;


SELECT   a.session_id, s.osuser, s.machine, s.program, o.owner, o.object_name,
         o.object_type, a.event,
         SUM (a.wait_time + a.time_waited) total_wait_time
    FROM v$active_session_history a, dba_objects o, v$session s
   WHERE a.sample_time BETWEEN SYSDATE - 30 / 2880 AND SYSDATE
     AND a.current_obj# = o.object_id
     AND a.session_id = s.SID
GROUP BY o.owner,
         o.object_name,
         o.object_type,
         a.event,
         a.session_id,
         s.program,
         s.machine,
         s.osuser
ORDER BY total_wait_time DESC;



8.查询当前连接会话数
select s.value,s.sid,a.username
from
v$sesstat S,v$statname N,v$session A
where
n.statistic#=s.statistic# and
name='session pga memory'
and s.sid=a.sid
order by s.value;



9.等待最多的用户
SELECT   s.SID, s.username, SUM (a.wait_time + a.time_waited) total_wait_time
    FROM v$active_session_history a, v$session s
   WHERE a.sample_time BETWEEN SYSDATE - 30 / 2880 AND SYSDATE
GROUP BY s.SID, s.username
ORDER BY total_wait_time DESC;



10.等待最多的SQL
SELECT   a.program, a.session_id, a.user_id, d.username, s.sql_text,
         SUM (a.wait_time + a.time_waited) total_wait_time
    FROM v$active_session_history a, v$sqlarea s, dba_users d
   WHERE a.sample_time BETWEEN SYSDATE - 30 / 2880 AND SYSDATE
     AND a.sql_id = s.sql_id
     AND a.user_id = d.user_id
GROUP BY a.program, a.session_id, a.user_id, s.sql_text, d.username;



11.查看消耗资源最多的SQL
SELECT hash_value, executions, buffer_gets, disk_reads, parse_calls
FROM V$SQLAREA
WHERE buffer_gets > 10000000 OR disk_reads > 1000000
ORDER BY buffer_gets + 100 * disk_reads DESC;



12.查看某条SQL语句的资源消耗
SELECT hash_value, buffer_gets, disk_reads, executions, parse_calls
FROM V$SQLAREA
WHERE hash_Value = 228801498 AND address = hextoraw('CBD8E4B0');


13.查询会话执行的实际SQL
SELECT   a.SID, a.username, s.sql_text
    FROM v$session a, v$sqltext s
   WHERE a.sql_address = s.address
     AND a.sql_hash_value = s.hash_value
     AND a.status = 'ACTIVE'
ORDER BY a.username, a.SID, s.piece;


14.显示正在等待锁的所有会话
SELECT * FROM DBA_WAITERS;