--在某个用户下找所有的索引select user_indexes.table_name, user_indexes.index_name,uniqueness, column_namefrom user_ind_columns, user_indexeswhere user_ind_columns.index_name = user_indexes.index_nameand 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;--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$filestat f,dba_data_files dfwhere f.file#=df.file_id--监控 SGA 中字典缓冲区的命中率select parameter, gets,Getmisses , getmisses/(gets+getmisses)*100 "miss ratio",(1-(sum(getmisses)/ (sum(gets)+sum(getmisses))))*100 "Hit ratio"from v$rowcache where gets+getmisses <>0group by parameter, gets, getmisses;--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$sysstat cwhere a.statistic# = 38 and b.statistic# = 39 and c.statistic# = 40;--监控内存和硬盘的排序比率，最好使它小于 .10，增加 sort_area_sizeSELECT name, value FROM v$sysstat WHERE name IN ('sorts (memory)', 'sorts (disk)');--查看碎片程度高的表SELECT segment_name table_name , COUNT(*) extentsFROM dba_segments WHERE owner NOT IN ('SYS', 'SYSTEM') GROUP BY segment_nameHAVING COUNT(*) = (SELECT MAX( COUNT(*) ) FROM dba_segments GROUP BY segment_name);--找使用CPU多的用户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$sesstat c where c.statistic#=12 and c.sid=a.sid and a.paddr=b.addr order by value desc;--监控log_buffer的使用情况：(值最好小于1%，否则增加log_buffer 的大小)select rbar.name,rbar.value,re.name,re.value,(rbar.value*100)/re.value||'%' "radio" from v$sysstat rbar,v$sysstat re where rbar.name='redo buffer allocation retries' and re.name='redo entries';

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