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;
查找当前表级锁的SQL
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;
杀掉锁表进程
alter system kill session '436,35123';
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;
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;
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$sesstat c where c.statistic#=12 and c.sid=a.sid and a.paddr=b.addr order by value desc;
查看死锁信息
SELECT (SELECT username FROM v$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$lock b WHERE a.BLOCK = 1 AND b.request > 0 AND a.id1 = b.id1 AND a.id2 = b.id2;
具有最高等待的对象
SELECT o.OWNER,o.object_name, o.object_type, a.event, SUM (a.wait_time + a.time_waited) total_wait_time FROM v$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
查询当前连接会话数
select s.value,s.sid,a.username from v$sesstat S,v$statname N,v$session A where n.statistic#=s.statistic# and name='session pga memory' and s.sid=a.sid order by s.value;
等待最多的用户
SELECT s.SID, s.username, SUM (a.wait_time + a.time_waited) total_wait_time FROM v$active_session_history a, v$session s WHERE a.sample_time BETWEEN SYSDATE - 30 / 2880 AND SYSDATE GROUP BY s.SID, s.username ORDER BY total_wait_time DESC;
等待最多的SQL
SELECT a.program, a.session_id, a.user_id, d.username, s.sql_text, SUM (a.wait_time + a.time_waited) total_wait_time FROM v$active_session_history a, v$sqlarea s, dba_users d WHERE a.sample_time BETWEEN SYSDATE - 30 / 2880 AND SYSDATE AND a.sql_id = s.sql_id AND a.user_id = d.user_id GROUP BY a.program, a.session_id, a.user_id, s.sql_text, d.username;
查看消耗资源最多的SQL
SELECT hash_value, executions, buffer_gets, disk_reads, parse_calls FROM V$SQLAREA WHERE buffer_gets > 10000000 OR disk_reads > 1000000 ORDER BY buffer_gets + 100 * disk_reads DESC;
查看某条SQL语句的资源消耗
SELECT hash_value, buffer_gets, disk_reads, executions, parse_calls
FROM V$SQLAREA
WHERE hash_Value = 228801498 AND address = hextoraw('CBD8E4B0');查询会话执行的实际SQL
SELECT a.SID, a.username, s.sql_text FROM v$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;
显示正在等待锁的所有会话
SELECT * FROM DBA_WAITERS;
原创文章请注明转载自技术小站本文地址：http://www.i5i6.net/post/110.html，标题：Oracel 一些常用语句
