Oracle常用SQL

--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;