监控Oracle性能的SQL
Roc.Ken
|
1#
Roc.Ken 发表于 2007-05-25 14:21
监控Oracle性能的SQL
FROM chinaunix.net BY geniiking
1. 监控事例的等待
复制内容到剪贴板
2. 回滚段的争用情况
代码:select event,sum(decode(wait_Time,0,0,1)) "Prev",sum(decode(wait_Time,0,1,0)) "Curr",count(*) "Tot" from v$session_Wait group by event order by 4;
复制内容到剪贴板
3. 监控表空间的 I/O 比例
代码:select name, waits, gets, waits/gets "Ratio"from v$rollstat a, v$rollname b where a.usn = b.usn;
复制内容到剪贴板
4. 监控文件系统的 I/O 比例
代码:select df.tablespace_name name,df.file_name "file",f.phyrds pyr,f.phyblkrd pbr,f.phywrts pyw, f.phyblkwrt pbw from v$filestat f, dba_data_files df where f.file# = df.file_id order by df.tablespace_name;
复制内容到剪贴板
5.在某个用户下找所有的索引
代码: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#;
复制内容到剪贴板
6. 监控 SGA 的命中率
代码:select user_indexes.table_name, user_indexes.index_name,uniqueness, column_namefrom 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;
复制内容到剪贴板
7. 监控 SGA 中字典缓冲区的命中率
代码: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$sysstat c where a.statistic# = 38 and b.statistic# = 39 and c.statistic# = 40;
复制内容到剪贴板
8. 监控 SGA 享缓存区的命中率,应该小于1%
代码:select parameter, gets,Getmisses , getmisses/(gets+getmisses)*100 "miss ratio",(1-(sum(getmisses)/ (sum(gets)+sum(getmisses))))*100 "Hit ratio" from v$rowcache where gets+getmisses <>;0 group by parameter, gets, getmisses;
复制内容到剪贴板
9. 显示所有数据库对象的类别和大小
代码: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;
复制内容到剪贴板
10. 监控 SGA 中重做日志缓存区的命中率,应该小于1%
代码: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;
复制内容到剪贴板
11. 监控内存和硬盘的排序比率,最好使它小于 .10,增加 sort_area_size
代码: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$latch WHERE name IN ('redo allocation', 'redo copy');
复制内容到剪贴板
12. 监控当前数据库谁在运行什么SQL语句
代码:SELECT name, value FROM v$sysstat WHERE name IN ('sorts (memory)', 'sorts (disk)');
复制内容到剪贴板
13. 监控字典缓冲区
代码:SELECT osuser, username, sql_text from v$session a, v$sqltext bwhere a.sql_address =b.address order by address, piece;
复制内容到剪贴板
后者除以前者,此比率小于1%,接近0%为好。
代码: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$LIBRARYCACHE;
复制内容到剪贴板
14. 找ORACLE字符集
代码:SELECT SUM(GETS) "DICTIONARY GETS",SUM(GETMISSES) "DICTIONARY CACHE GET MISSES"FROM V$ROWCACHE
复制内容到剪贴板
15. 监控 MTS
代码:select * from sys.props$ where name='NLS_CHARACTERSET';
复制内容到剪贴板
此值大于0.5时,参数需加大
代码:select busy/(busy+idle) "shared servers busy" from v$dispatcher;
复制内容到剪贴板
servers_highwater接近mts_max_servers时,参数需加大代码:select sum(wait)/sum(totalq) "dispatcher waits" from v$queue where type='dispatcher';select count(*) from v$dispatcher; select servers_highwater from v$mts; 16. 碎片程度
复制内容到剪贴板
查看碎片程度高的表
代码:select tablespace_name,count(tablespace_name) from dba_free_space group by tablespace_namehaving 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;
复制内容到剪贴板
17. 表、索引的存储情况检查
代码:SELECT segment_name table_name , COUNT(*) extentsFROM dba_segments WHERE owner NOT IN ('SYS', 'SYSTEM') GROUP BY segment_name HAVING COUNT(*) = (SELECT MAX( COUNT(*) ) FROM dba_segments GROUP BY segment_name);
复制内容到剪贴板
18、找使用CPU多的用户session
代码:select segment_name,sum(bytes),count(*) ext_quan from dba_extents wheretablespace_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 owner='&owner' group by segment_name;
复制内容到剪贴板
代码:12是cpu used by this sessionselect 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; |