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;