Oracle常用查询

--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,

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;