1. 监控事例的等待 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$rollname b where a.usn = b.usn; 3. 监控表空间的 I/O 比例 select df.tablespace_name name,df.file_name "file",f.phyrds pyr, f.phyblkrd pbr,f.phywrts pyw, f.phyblkwrt pbw from v$filestat f, dba_data_files df where f.file# = df.file_id order by df.tablespace_name; 4. 监控文件系统的 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. 监控 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$sysstat c where a.statistic# = 38 and b.statistic# = 39 and c.statistic# = 40; 7. 监控 SGA 中字典缓冲区的命中率 select parameter, gets,Getmisses , getmisses/(gets+getmisses)*100 "miss ratio", (1-(sum(getmisses)/ (sum(gets)+sum(getmisses))))*100 "Hit ratio" from v$rowcache where gets+getmisses <>0 group by parameter, gets, getmisses; 8. 监控 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. 监控 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$latch WHERE name IN ('redo allocation', 'redo copy'); 11. 监控内存和硬盘的排序比率，最好使它小于 .10，增加 sort_area_size SELECT name, value FROM v$sysstat WHERE name IN ('sorts (memory)', 'sorts (disk)');

12. 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; 13. 监控字典缓冲区 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. 监控 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) space,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 owner='&owner' group by segment_name;    1. 检测数据库中的事件和等待        SELECT event, total_waits, total_timeouts,time_waited, average_wait        FROM v$system_event 2. 查询会话中的事件和等待时间        select sid, event, total_waits,average_wait        from v$session_event where sid=10;     3. 查询等待进程        SELECT sid, seq#, event, wait_time, state        FROM v$session_wait; 4. 监控全局区的性能        select * from v$sgastat; 5. 查询命中率        select gethitratio        from v$librarycache        where namespace = 'SQL AREA'; 6. 当前 sql 语句        select sql_text, users_executing,        executions, loads        from v$sqlarea; 7. 查询高速缓存中的命中率        select sum(pins) "Executions", sum(reloads) "Cache Misses",        sum(reloads)/sum(pins)        from v$librarycache; 8. 查询全局字典中的有效装载次数        select namespace,pins,reloads,invalidations        from v$librarycache; 9. 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; 10. 监控表空间的 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$filestat f, dba_data_files df     where f.file# = df.file_id     order by df.tablespace_name; 11. 监控文件系统的 I/O 比例    select substr(a.file#,1,2) "#", substr(a.name,1,30) "Name",     a.status, a.bytes, b.phyrds, b.phywrts     from v$datafile a, v$filestat b     where a.file# = b.file#; 12. 在某个用户下找所有的索引     select user_indexes.table_name, user_indexes.index_name,uniqueness, column_name     from user_ind_columns, user_indexes     where user_ind_columns.index_name = user_indexes.index_name     and user_ind_columns.table_name = user_indexes.table_name     order by user_indexes.table_type, user_indexes.table_name, user_indexes.index_name, column_position; 13. 监控 SGA 中字典缓冲区的命中率     select parameter, gets,Getmisses , getmisses/(gets+getmisses)*100 "miss ratio",     (1-(sum(getmisses)/ (sum(gets)+sum(getmisses))))*100 "Hit ratio"     from v$rowcache     where gets+getmisses <>0     group by parameter, gets, getmisses; 14. 监控 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; 15. 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; 16. 监控 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$latch WHERE name IN ('redo allocation', 'redo copy'); 17. 监控内存和硬盘的排序比率，最好使它小于 .10 ，增加 sort_area_size SELECT name, value FROM v$sysstat WHERE name IN ('sorts (memory)', 'sorts (disk)'); 18. 监控字典缓冲区

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 19. 找 ORACLE 字符集    select * from sys.props$ where name='NLS_CHARACTERSET'; 20. 监控 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 21. 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); 22. 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 owner='&owner'     group by segment_name; 23 、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;

作者“anyonefeng”