Oracle数据库一些实践(best practise)

Oracle数据库提供了强大的数据字典视图和动态性能视图,但这些视图大多数晦涩难懂,就算专业的DBA也难以将所有的视图用好.这里列举了一些常用的数据库管理的命令

-- 查看当前的正在运行的SQL语句
SELECT t.Addr, t.Start_Time, Ss.Sid, Ss.Username, s.Sql_Text, Sp.Sql_Text
  FROM V$transaction t, V$session Ss, V$sql s, V$sql Sp
 WHERE Ss.Taddr = t.Addr
   AND Ss.Sql_Id = s.Sql_Id(+)
   AND Ss.Prev_Sql_Id = Sp.Sql_Id(+)

-- 查看导致数据锁的SQL语句
select /*+ ordered */ a.sid blocker_sid, a.username blocker_username, a.serial#, a.logon_time, b.type, b.lmode mode_held, b.ctime time_held, c.sid waiter_sid, c.request request_mode, c.ctime time_waited
from v$lock b, v$enqueue_lock c, v$session a
where a.sid = b.sid
and b.id1 = c.id1(+)
and b.id2 = c.id2(+)
and c.type(+) = 'TX'
and b.type = 'TX'
and b.block = 1
order by time_held, time_waited;

-- 查看数据库表空间使用量
SELECT Dbf.Tablespace_Name,
       Dbf.Totalspace AS "Total (MB)",
       round(Dbf.Totalspace - Dfs.Freespace,2) AS "Used (MB)",
       substr('>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>',1,trunc((Dbf.Totalspace - Dfs.Freespace) / Dbf.Totalspace * 100 / 2))||
       substr('--------------------------------------------------',1,49-trunc((Dbf.Totalspace - Dfs.Freespace) / Dbf.Totalspace * 100 / 2)) AS "Percent Bar",
       round((Dbf.Totalspace - Dfs.Freespace) / Dbf.Totalspace * 100,1) AS "Used Percent",
       round(Dfs.Freespace,2) AS "Free (MB)"
  FROM (SELECT t.Tablespace_Name,
               SUM(t.Bytes) / 1024 / 1024 Totalspace,
               SUM(t.Blocks) Totalblocks
          FROM Dba_Data_Files t
         GROUP BY t.Tablespace_Name,t.file_name) Dbf,
       (SELECT Tt.Tablespace_Name,
               SUM(Tt.Bytes) / 1024 / 1024 Freespace,
               SUM(Tt.Blocks) Freeblocks
          FROM Dba_Free_Space Tt
         GROUP BY Tt.Tablespace_Name) Dfs
 WHERE TRIM(Dbf.Tablespace_Name) = TRIM(Dfs.Tablespace_Name)
 ORDER BY Tablespace_Name;

本文出自 “数据海洋” 博客，谢绝转载！