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oracle数据库性能监视

原创 Linux操作系统 作者:luoyanqing119 时间:2009-06-10 10:10:29 0 删除 编辑
 oracle数据库性能监视的SQL

  转载:世纪易网 整理:playboy

  1. 监视事例的等待

  select event,sum(decode(wait_Time,0,0,1)) "Prev",

  sum(decode(wait_Time,0,1,0)) "Curr",count(*) "Tot"

  from v$session_Wait

  group by event order by 4;

  2. 回滚段的争用情况

  select name, waits, gets, waits/gets "Ratio"

  from v$rollstat a, v$rollname b

  where a.usn = b.usn;

  3. 监视表空间的 I/O 比例

  select df.tablespace_name name,df.file_name "file",f.phyrds pyr,

  f.phyblkrd pbr,f.phywrts pyw, f.phyblkwrt pbw

  from v$filestat f, dba_data_files df

  where f.file# = df.file_id

  order by df.tablespace_name;

  4. 监视文件系统的 I/O 比例

  select substr(a.file#,1,2) "#", substr(a.name,1,30) "Name",

  a.status, a.bytes, b.phyrds, b.phywrts

  from v$datafile a, v$filestat b

  where a.file# = b.file#;

  5.在某个用户下找所有的索引

  select user_indexes.table_name, user_indexes.index_name,uniqueness, column_name

  from user_ind_columns, user_indexes

  where user_ind_columns.index_name = user_indexes.index_name

  and user_ind_columns.table_name = user_indexes.table_name

  order by user_indexes.table_type, user_indexes.table_name,

  user_indexes.index_name, column_position;

  6. 监视 SGA 的命中率

  select a.value + b.value "logical_reads", c.value "phys_reads",

  round(100 * ((a.value+b.value)-c.value) / (a.value+b.value)) "BUFFER HIT RATIO"

  from v$sysstat a, v$sysstat b, v$sysstat c

  where a.statistic# = 38 and b.statistic# = 39

  and c.statistic# = 40;

  7. 监视 SGA 中字典缓冲区的命中率

  select parameter, gets,Getmisses , getmisses/(gets+getmisses)*100 "miss ratio",

  (1-(sum(getmisses)/ (sum(gets)+sum(getmisses))))*100 "Hit ratio"

  from v$rowcache

  where gets+getmisses <>0

  group by parameter, gets, getmisses;

  8. 监视 SGA 中共享缓存区的命中率,应该小于1%

  select sum(pins) "Total Pins", sum(reloads) "Total Reloads",

  sum(reloads)/sum(pins) *100 libcache

  from v$librarycache;

  select sum(pinhits-reloads)/sum(pins) "hit radio",sum(reloads)/sum(pins) "reload percent"

  from v$librarycache;

  9. 显示所有数据库对象的类别和大小

  select count(name) num_instances ,type ,sum(source_size) source_size ,

  sum(parsed_size) parsed_size ,sum(code_size) code_size ,sum(error_size) error_size,

  sum(source_size) +sum(parsed_size) +sum(code_size) +sum(error_size) size_required

  from dba_object_size

  group by type order by 2;

  10. 监视 SGA 中重做日志缓存区的命中率,应该小于1%

  SELECT name, gets, misses, immediate_gets, immediate_misses,

  Decode(gets,0,0,misses/gets*100) ratio1,

  Decode(immediate_gets+immediate_misses,0,0,

  immediate_misses/(immediate_gets+immediate_misses)*100) ratio2

  FROM v$latch WHERE name IN (’redo allocation’, ’redo copy’);

  11. 监视内存和硬盘的排序比率,最佳使他小于 .10,增加 sort_area_size

  SELECT name, value FROM v$sysstat WHERE name IN (’sorts (memory)’, ’sorts (disk)’);

  12. 监视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;

  13. 监视字典缓冲区

  SELECT (SUM(PINS - RELOADS)) / SUM(PINS) "LIB CACHE" FROM V$LIBRARYCACHE;

  SELECT (SUM(GETS - GETMISSES - USAGE - FIXED)) / SUM(GETS) "ROW CACHE" FROM V$ROWCACHE;

  SELECT SUM(PINS) "EXECUTIONS", SUM(RELOADS) "CACHE MISSES WHILE EXECUTING" FROM V$LIBRARYCACHE;

  后者除以前者,此比率小于1%,接近0%为好。

  SELECT SUM(GETS) "DICTIONARY GETS",SUM(GETMISSES) "DICTIONARY CACHE GET MISSES"

  FROM V$ROWCACHE

  14. 找ORACLE字符集

  select * from sys.props$ where name=’NLS_CHARACTERSET’;

  15. 监视 MTS

  select busy/(busy+idle) "shared servers busy" from v$dispatcher;

  此值大于0.5时,参数需加大

  select sum(wait)/sum(totalq) "dispatcher waits" from v$queue where type=’dispatcher’;

  select count(*) from v$dispatcher;

  select servers_highwater from v$mts;

  servers_highwater接近mts_max_servers时,参数需加大

  16. 碎片程度

  select tablespace_name,count(tablespace_name) from dba_free_space group by tablespace_name

  having count(tablespace_name)>10;

  alter tablespace name coalesce;

  alter table name deallocate unused;

  create or replace view ts_blocks_v as

  select tablespace_name,block_id,bytes,blocks,’free space’ segment_name from dba_free_space

  union all

  select tablespace_name,block_id,bytes,blocks,segment_name from dba_extents;

  select * from ts_blocks_v;

  select tablespace_name,sum(bytes),max(bytes),count(block_id) from dba_free_space

  group by tablespace_name;

  查看碎片程度高的表

  SELECT segment_name table_name , COUNT(*) extents

  FROM dba_segments WHERE owner NOT IN (’SYS’, ’SYSTEM’) GROUP BY segment_name

  HAVING COUNT(*) = (SELECT MAX( COUNT(*) FROM dba_segments GROUP BY segment_name);

  17. 表、索引的存储情况检查

  select segment_name,sum(bytes),count(*) ext_quan from dba_extents where

  tablespace_name=’&tablespace_name’ and segment_type=’TABLE’ group by tablespace_name,segment_name;

  select segment_name,count(*) from dba_extents where segment_type=’INDEX’ and wner=’&owner’

  group by segment_name;

  18、找使用CPU多的用户session

  12是cpu used by this 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;

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