常用监控SQL.doc

常用监控SQL 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(*)from v$session_waitgroup by event order by 4;2.回滚段的争用情况：select name,waits,gets,waits/gets ratio from v$rollstat a,v$rollname b where a.usn=b.usn;3.监控表空间的I/O比例：select df.tablespace_name name,df.file_name file,f.phyrds pyr,f.phyblkrd pbr,f.phywrts pyw,f.phyblkwrt pbwfrom v$filestat f,dba_data_files dfwhere f.file#=df.file_id4.监空文件系统的I/O比例：select substr(a.file#,1,2) #,substr(a.name,1,30) name,a.status,a.bytes,b.phyrds,b.phywrtsfrom v$datafile a,v$filestat bwhere 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_namefrom user_ind_columns, user_indexeswhere user_ind_columns.index_name = user_indexes.index_nameand user_ind_columns.table_name = user_indexes.table_nameorder 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 RATIOfrom v$sysstat a, v$sysstat b, v$sysstat cwhere a.statistic# = 38 and b.statistic# = 39and c.statistic# = 40;7. 监控 SGA 中字典缓冲区的命中率select parameter, gets,Getmisses , getmisses/(gets+getmisses)*100 miss ratio,(1-(sum(getmisses)/ (sum(gets)+sum(getmisses))))*100 Hit ratiofrom v$rowcachewhere gets+getmisses 0group 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 libcachefrom v$librarycache;select sum(pinhits-reloads)/sum(pins) hit radio,sum(reloads)/sum(pins) reload percentfrom v$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_requiredfrom dba_object_sizegroup b