--用于查看哪些實例的哪些操作使用了大量的臨時段
SELECT to_number(decode(SID, 65535, NULL, SID)) sid,
Operation_type OPERATION,trunc(EXPECTED_SIZE/1024) ESIZE,
trunc(ACTUAL_MEM_USED/1024) MEM, trunc(MAX_MEM_USED/1024) "MAX MEM",
NUMBER_PASSES PASS, trunc(TEMPSEG_SIZE/1024) TSIZE
FROM V$SQL_WORKAREA_ACTIVE
ORDER BY 1,2;
---查詢有熱塊查詢的SQL語句
select hash_value
from v$sqltext a,
(select distinct a.owner,a.segment_name,a.segment_type from
dba_extents a,
(select dbarfil,dbablk
from (select dbarfil,dbablk
from x$bh order by tch desc) where rownum < 11) b
where a.RELATIVE_FNO = b.dbarfil
and a.BLOCK_ID <= b.dbablk and a.block_id + a.blocks > b.dbablk) b
where a.sql_text like '%'b.segment_name'%' and b.segment_type = 'TABLE'
order by a.hash_value,a.address,a.piece;
--全表掃描
select opname,target,b.num_rows,b.tablespace_name,count(target) from v$session_longops a,all_all_tables b
where a.TARGET=b.owner'.'b.table_name
having count(target)>10 group by opname,target,b.num_rows,b.tablespace_name
--查看磁盤排序和緩存排序次數
select to_char(sn.snap_time,'yyyy-mm-dd hh24') time_,
avg(newmen.value - oldmen.value) sorts_memeory,
avg(newdsk.value - olddsk.value) disk_sort
from stats$sysstat oldmen,
stats$sysstat newmen,
stats$sysstat newdsk,
stats$sysstat olddsk,
stats$snapshot sn
where newdsk.snap_id=sn.snap_id
and olddsk.snap_id=sn.snap_id-1
and newmen.snap_id=sn.snap_id
and newdsk.snap_id=sn.snap_id -1
and oldmen.name='sorts (memory)'
and newmen.name='sorts (memory)'
and olddsk.name='sorts (disk)'
and newdsk.name='sorts (disk)'
group by to_char(sn.snap_time,'yyyy-mm-dd hh24')
--執行最慢的前10個SQL？？？
select * from (
select
to_char(snap_time,'dd Mon HH24:mi:ss') mydate,
executions exec,
loads loads,
parse_calls parse,
disk_reads reads,
buffer_gets gets,
rows_PRocessed rows_proc,
sorts sorts,
sql_text,
hash_value
from
perfstat.stats$sql_summary sql,
perfstat.stats$snapshot sn
where
sql.snap_id >
(select min(snap_id) min_snap
from stats$snapshot where snap_time > sysdate-$days_back)
and
sql.snap_id = sn.snap_id
order by $sortskey desc) tt where rownum<11;
--SQL緩存池的命中率查詢（pinhitratio，gethitratio應該大于90%以上）
select namespace,gethitratio,pinhitratio,reloads,invalidations
from v$librarycache
where namespace in ('SQL AREA','TABLE/PROCEDURE','BODY','TRIGGER')
--數據庫的常規參數我就不說了，除了V$parameter中的常規參數外，Oracle還有大量的隱含參數，下面的語句就可以查詢到數據庫的所有隱含參數以及其值與參數的描述。
SELECT NAME
,VALUE
,decode(isdefault, 'TRUE','Y','N') as "Default"
,decode(ISEM,'TRUE','Y','N') as SesMod
,decode(ISYM,'IMMEDIATE', 'I',
'DEFERRED', 'D',
'FALSE', 'N') as SysMod
,decode(IMOD,'MODIFIED','U',
'SYS_MODIFIED','S','N') as Modified
,decode(IADJ,'TRUE','Y','N') as Adjusted
,description
FROM ( --GV$SYSTEM_PARAMETER
SELECT x.inst_id as instance
,x.indx+1
,ksppinm as NAME
,ksppity
,ksppstvl as VALUE
,ksppstdf as isdefault
,decode(bitand(ksppiflg/256,1),1,'TRUE','FALSE') as ISEM
,decode(bitand(ksppiflg/65536,3),
1,'IMMEDIATE',2,'DEFERRED','FALSE') as ISYM
,decode(bitand(ksppstvf,7),1,'MODIFIED','FALSE') as IMOD
,decode(bitand(ksppstvf,2),2,'TRUE','FALSE') as IADJ
,ksppdesc as DESCRIPTION
FROM x$ksppi x
,x$ksppsv y
WHERE x.indx = y.indx
AND substr(ksppinm,1,1) = '_'
AND x.inst_id = USERENV('Instance')
)
ORDER BY NAME
--想知道現在哪個用戶正在利用臨時段嗎？這個語句將告訴你哪個用戶正在利用臨時段。
SELECT b.tablespace, b.segfile#, b.segblk#, b.blocks, a.sid, a.serial#,
a.username, a.osuser, a.status,c.sql_text
FROM v$session a,v$sort_usage b, v$sql c
WHERE a.saddr = b.session_addr
AND a.sql_address = c.address(+)
ORDER BY b.tablespace, b.segfile#, b.segblk#, b.blocks;
--查看磁盤碎片
select tablespace_name,sqrt(max(blocks)/sum(blocks))*
(100/sqrt(sqrt(count(blocks)))) FSFI
from dba_free_space
group by tablespace_name order by 1
1.查看表空間的名稱及大小
select t.tablespace_name, round(sum(bytes/(1024*1024)),0) ts_size
from dba_tablespaces t, dba_data_files d
where t.tablespace_name = d.tablespace_name
group by t.tablespace_name;
2.查看表空間物理文件的名稱及大小
select tablespace_name, file_id, file_name,
round(bytes/(1024*1024),0) total_space
from dba_data_files
order by tablespace_name;
3.查看回滾段名稱及大小
select segment_name, tablespace_name, r.status,
(initial_extent/1024) InitialExtent,(next_extent/1024) NextExtent,
max_extents, v.curext CurExtent
From dba_rollback_segs r, v$rollstat v
Where r.segment_id = v.usn(+)
order by segment_name
15。耗資源的進程（top session)
select s.schemaname schema_name, decode(sign(48 - command), 1,
to_char(command), 'Action Code #' to_char(command) ) action, status
session_status, s.osuser os_user_name, s.sid, p.spid , s.serial# serial_num,
nvl(s.username, '[Oracle process]') user_name, s.terminal terminal,
s.program program, st.value criteria_value from v$sesstat st, v$session s , v$process p
where st.sid = s.sid and st.statistic# = to_number('38') and ('ALL' = 'ALL'
or s.status = 'ALL') and p.addr = s.paddr order by st.value desc, p.spid asc, s.username asc, s.osuser asc
16。
查看鎖（lock）情況
select /*+ RULE */ ls.osuser os_user_name, ls.username user_name,
decode(ls.type, 'RW', 'Row wait enqueue lock', 'TM', 'DML enqueue lock', 'TX',
'Transaction enqueue lock', 'UL', 'User supplied lock') lock_type,
o.object_name object, decode(ls.lmode, 1, null, 2, 'Row Share', 3,
'Row Exclusive', 4, 'Share', 5, 'Share Row Exclusive', 6, 'Exclusive', null)
lock_mode, o.owner, ls.sid, ls.serial# serial_num, ls.id1, ls.id2
from sys.dba_objects o, ( select s.osuser, s.username, l.type,
l.lmode, s.sid, s.serial#, l.id1, l.id2 from v$session s,
v$lock l where s.sid = l.sid ) ls where o.object_id = ls.id1 and o.owner
<> 'SYS' order by o.owner, o.object_name
--查看低效率的SQL語句
SELECT EXECUTIONS , DISK_READS, BUFFER_GETS,
ROUND((BUFFER_GETS-DISK_READS)/BUFFER_GETS,2) Hit_radio,
ROUND(DISK_READS/EXECUTIONS,2) Reads_per_run,
SQL_TEXT
FROM V$SQLAREA
WHERE EXECUTIONS>0
AND BUFFER_GETS > 0
AND (BUFFER_GETS-DISK_READS)/BUFFER_GETS < 0.8
ORDER BY 4 DESC
