个人整理巡检脚本，求大家拍砖~
------------------------------SGA-----------------------------------------------SGA 各部分大小
show sga
select * from v$sga;
SELECT * FROM V$SGAINFO;
--SGA设置大小
show parameter sga_target
--SGA各个池大小
COL name FORMAT a32;
SELECT pool, name, bytes/1024/1024 M
FROM v$sgastat
WHERE pool IS NULL
OR pool != 'shared pool'
OR (pool = 'shared pool' AND
(name IN
('dictionary cache', 'enqueue', 'library
cache', 'parameters', 'processes', 'sessions', 'free memory')))
ORDER BY pool DESC NULLS FIRST, name;
------------------------BUFFER CACHE-----------------------------------------------
--查看buffer cache 命中率
select 1 - (sum(decode(name, 'physical reads', value, 0)) /
(sum(decode(name, 'db block gets', value, 0)) +
(sum(decode(name, 'consistent gets', value, 0))))) "Buffer Hit Ratio"
from v$sysstat;
select name,
physical_reads,
(consistent_gets + db_block_gets) logic_reads,
1 - (physical_reads) / (consistent_gets + db_block_gets) hit_radio
from v$buffer_pool_statistics;
--查看buffer cache建议
select size_for_estimate,
estd_physical_read_factor,
to_char(estd_physical_reads, 99999999999999999999999) as"estd_physical_reads"
from v$db_cache_advice
where name = 'DEFAULT';
--查看buffer cache建议 --适用于指定SGA的目的
COL pool FORMAT a10;
SELECT (SELECT ROUND(value / 1024 / 1024, 0)
FROM v$parameter
WHERE name = 'db_cache_size') "Current Cache(Mb)",
name "Pool",
size_for_estimate "Projected Cache(Mb)",
ROUND(100 - estd_physical_read_factor, 0) "Cache Hit Ratio%"
FROM v$db_cache_advice
WHERE block_size = (SELECT value FROM v$parameter WHERE name = 'db_block_size')
ORDER BY 3;
--查看cache
show parameter cache
--各种读取的统计
---Database read buffer cache hit ratio =
---1 – (physical reads / (db block gets + consistent gets))
SELECT to_char(value,'9999999999999'), name FROM V$SYSSTAT WHERE name IN
('physical reads', 'db block gets', 'consistent gets');
SELECT 'Database Buffer Cache Hit Ratio ' "Ratio"
, ROUND((1-
((SELECT SUM(value) FROM V$SYSSTAT WHERE name = 'physical reads')
/ ((SELECT SUM(value) FROM V$SYSSTAT WHERE name = 'db block gets')
+ (SELECT SUM(value) FROM V$SYSSTAT WHERE name = 'consistent gets')
))) * 100)||'%' "Percentage"
FROM DUAL;
------------------------SHARED_POOL-----------------------------------------------
show parameter shared
---检查整体命中率(library cache)
select sum(pinhits) get ,
sum(pins)-sum(pinhits) miss,
sum(pinhits) / sum(pins)
from v$librarycache;
-- 查看library cache 命中率（分类）
select t.NAMESPACE,t.GETHITRATIO*100
from v$librarycache t;
select sum(pins) "hits",
sum(reloads) "misses",
sum(pins) / (sum(pins) + sum(reloads)) "Hits Ratio"
from v$librarycache;e
---检查shered poolfreespace
SELECT *
FROM V$SGASTAT
WHERE NAME = 'free memory'
AND POOL = 'shared pool';
---检查row cache(数据字典缓冲区)命中率
---当执行一个dml或ddl都会造成对数据字典的递归修改
column updates format 999,999,999
SELECT parameter
, sum(gets)
, sum(getmisses)
, 100*sum(gets - getmisses) / sum(gets)pct_succ_gets
, sum(modifications) updates
FROM V$ROWCACHE
WHERE gets > 0
GROUP BY parameter;
SELECT (SUM(GETS - GETMISSES - FIXED)) / SUM(GETS) "ROW CACHE"
FROM V$ROWCACHE;
---查看Shared pool latch(多池技术)
/*col parameter for a20
col session for a20*/
select a.ksppinm "Parameter",
b.ksppstvl "Session Value",
c.ksppstvl "Instance Value"
from sys.x$ksppi a, sys.x$ksppcv b, sys.x$ksppsv c
where a.indx = b.indx and a.indx = c.indx
and a.ksppinm = '_kghdsidx_count';
---查看shared pool建议
column c1 heading 'Pool |Size(M)'
column c2 heading 'Size|Factor'
column c3 heading 'Est|LC(M)'
column c4 heading 'Est LC|Mem. Obj.'
column c5 heading 'Est|Time|Saved|(sec)'
column c6 heading 'Est|Parse|Saved|Factor'
column c7 heading 'Est|Object Hits' format 999,999,999
SELECT shared_pool_size_for_estimate c1,
shared_pool_size_factor c2,
estd_lc_size c3,
estd_lc_memory_objects c4,
estd_lc_time_saved c5,
estd_lc_time_saved_factor c6,
to_char(estd_lc_memory_object_hits, 99999999999) c7
FROM V$SHARED_POOL_ADVICE;
--查看shared pool中 各种类型的chunk的大小数量
SELECT KSMCHCLS CLASS,
COUNT(KSMCHCLS) NUM,
SUM(KSMCHSIZ) SIZ,
To_char(((SUM(KSMCHSIZ) / COUNT(KSMCHCLS) / 1024)), '999,999.00') || 'k' "AVG SIzE"
FROM X$KSMSP
GROUP BY KSMCHCLS;
--查看是否有库缓冲有关的等待事件
select sid, seq#, event, p1, p1raw, p2, p2raw, p3, p3raw, state
from v$session_wait
where event like 'library%';
--row cache命中率
SELECT 'Dictionary Cache Hit Ratio ' "Ratio",
ROUND((1 - (SUM(GETMISSES) / SUM(GETS))) * 100, 2) || '%' "Percentage"
FROM V$ROWCACHE;
---library cache中详细比率信息
SELECT 'Library Lock Requests' "Ratio",
ROUND(AVG(gethitratio) * 100, 2) || '%' "Percentage"
FROM V$LIBRARYCACHE
UNION all
SELECT 'Library Pin Requests' "Ratio",
ROUND(AVG(pinhitratio) * 100, 2) || '%' "Percentage"
FROM V$LIBRARYCACHE
UNION all
SELECT 'Library I/O Reloads' "Ratio",
ROUND((SUM(reloads) / SUM(pins)) * 100, 2) || '%' "Percentage"
FROM V$LIBRARYCACHE ;
--查看library cache 内存分配情况(对哪类对象)
SELECT lc_namespace "Library",
LC_INUSE_MEMORY_OBJECTS "Objects",
LC_INUSE_MEMORY_SIZE "Objects Mb",
LC_FREEABLE_MEMORY_OBJECTS "Freeable Objects",
LC_FREEABLE_MEMORY_SIZE "Freeable Mb"
FROM v$library_cache_memory;
---查看使用shard_pool保留池情况
SELECT request_misses, request_failures, free_space
FROM v$shared_pool_reserved;
---查看cache中所有pool,命中情况
COL pool FORMAT a10;
SELECT a.name "Pool", a.physical_reads, a.db_block_gets
, a.consistent_gets
,(SELECT ROUND((1-(physical_reads / (db_block_gets + consistent_gets)))*100)
FROM v$buffer_pool_statistics
WHERE db_block_gets+consistent_gets != 0
AND name = a.name) "Ratio"
FROM v$buffer_pool_statistics a;
相关命令
--- alter table xx cache
---ALTER TABLE(INDEX) xx STORAGE(BUFFER_POOL KEEP);
---取消cache或keep(keep pool)
---ALTER TABLE XX NOCACHE;
---SELECT 'ALTER INDEX '||index_name||' STORAGE(BUFFER_POOL DEFAULT);'
---FROM USER_INDEXES WHERE BUFFER_POOL!='DEFAULT';
------------------------PGA-----------------------------------------------
---查看pga
show parameters area_size
--- 查看pga
SELECT * FROM v$pgastat;
--查看pga建议
SELECT (SELECT ROUND(value/1024/1024,0) FROM v$parameter
WHERE name = 'pga_aggregate_target') "Current Mb"
, ROUND(pga_target_for_estimate/1024/1024,0) "Projected Mb"
, ROUND(estd_pga_cache_hit_percentage) "%"
FROM v$pga_target_advice
ORDER BY 2;
------------------------其他指标类---------------------------------------
---查看数据库中行chain
SELECT 'Chained Rows ' "Ratio",
ROUND((SELECT SUM(value) FROM V$SYSSTATWHERE name = 'table fetch continued row')/
(SELECT SUM(value) FROM V$SYSSTATWHERE name IN ('table scan rows gotten', 'table fetch byrowid')
)* 100, 3)||'%' "Percentage"
FROM DUAL;
---在内存中排序比率(最优排序)
SELECT 'Sorts in Memory ' "Ratio",
ROUND((SELECT SUM(value) FROM V$SYSSTAT WHERE name = 'sorts (memory)') /
(SELECT SUM(value)
FROM V$SYSSTAT
WHERE name IN ('sorts (memory)', 'sorts (disk)')) * 100,
5) || '%' "Percentage"
FROM DUAL;
---查询解析比率
SELECT 'Soft Parses ' "Ratio",
ROUND(((SELECT SUM(value)
FROM V$SYSSTAT
WHERE name = 'parse count (total)') -
(SELECT SUM(value)
FROM V$SYSSTAT
WHERE name = 'parse count (hard)')) /
(SELECT SUM(value) FROM V$SYSSTAT WHERE name = 'execute count') * 100,
2) || '%' "Percentage"
FROM DUAL
UNION
SELECT 'Hard Parses ' "Ratio",
ROUND((SELECT SUM(value)
FROM V$SYSSTAT
WHERE name = 'parse count (hard)') /
(SELECT SUM(value) FROM V$SYSSTAT WHERE name = 'execute count') * 100,
2) || '%' "Percentage"
FROM DUAL
UNION
SELECT 'Parse Failures ' "Ratio",
ROUND((SELECT SUM(value)
FROM V$SYSSTAT
WHERE name = 'parse count (failures)') /
(SELECT SUM(value)
FROM V$SYSSTAT
WHERE name = 'parse count (total)') * 100,
5) || '%' "Percentage"
FROM DUAL;
--查询latch free 等待事件相关信息
COL event FORMAT a20;
COL waits FORMAT 9999990;
COL timeouts FORMAT 99999990;
COL average FORMAT 99999990;
SELECT event "Event",
time_waited "Total Time",
total_waits "Waits",
average_wait "Average",
total_timeouts "Timeouts"
FROM V$SYSTEM_EVENT
WHERE event = 'latch free'
ORDER BY EVENT;
---查看数据库中查询时主要访问方式,获取大表小表访问比率(2个表的访问算法不同)
---table scans (long tables)过多的话,一般db file scattered read比较显著
---_small_table_threshold来定义大表和小表的界限。缺省为2%的Buffer数量 ,>这个参数为大表
---default 大表的全表扫描会被置于LRU的末端(最近最少使用,冷端)，以期尽快老化(让其尽快换出buffer cache)，减少Buffer的占用
--表访问统计
SELECT value, name
FROM V$SYSSTAT
WHERE name IN ('table fetch by rowid',
'table scans (short tables)',
'table scans (long tables)');
-----查看大表小表扫描对应的值
SELECT value, name FROM V$SYSSTAT WHERE name IN
('table fetch by rowid', 'table scans (short tables)'
, 'table scans (long tables)');
SELECT 'Short to Long Full Table Scans' "Ratio"
, ROUND(
(SELECT SUM(value) FROM V$SYSSTAT
WHERE name = 'table scans (short tables)')
/ (SELECT SUM(value) FROM V$SYSSTAT WHERE name IN
('table scans (short tables)', 'table scans (long tables)'))
* 100, 2)||'%' "Percentage"
FROM DUAL
UNION
SELECT 'Short Table Scans ' "Ratio"
, ROUND(
(SELECT SUM(value) FROM V$SYSSTAT
WHERE name = 'table scans (short tables)')
/ (SELECT SUM(value) FROM V$SYSSTAT WHERE name IN
('table scans (short tables)', 'table scans (long tables)', 'table fetch by rowid'))
* 100, 2)||'%' "Percentage"
FROM DUAL
UNION
SELECT 'Long Table Scans ' "Ratio"
, ROUND(
(SELECT SUM(value) FROM V$SYSSTAT
WHERE name = 'table scans (long tables)')
/ (SELECT SUM(value) FROM V$SYSSTAT WHERE name
IN ('table scans (short tables)', 'table scans (long tables)', 'table fetch by rowid'))
* 100, 2)||'%' "Percentage"
FROM DUAL
UNION
SELECT 'Table by Index ' "Ratio"
, ROUND(
(SELECT SUM(value) FROM V$SYSSTAT WHERE name = 'table fetch by rowid')
/ (SELECT SUM(value) FROM V$SYSSTAT WHERE name
IN ('table scans (short tables)', 'table scans (long tables)'
, 'table fetch by rowid'))
* 100, 2)||'%' "Percentage"
FROM DUAL
UNION
SELECT 'Efficient Table Access ' "Ratio"
, ROUND(
(SELECT SUM(value) FROM V$SYSSTAT WHERE name
IN ('table scans (short tables)','table fetch by rowid'))
/ (SELECT SUM(value) FROM V$SYSSTAT WHERE name
IN ('table scans (short tables)', 'table scans (long tables)'
, 'table fetch by rowid'))
* 100, 2)||'%' "Percentage"
FROM DUAL;
redo 相关
--查询归档模式
select name ,open_mode,log_mode from v$database;
archive log list
---检查日志切换频率
select sequence#,
to_char(first_time, 'yyyymmdd_hh24:mi:ss') firsttime,
round((first_time - lag(first_time) over(order by first_time)) * 24 * 60,2) minutes
from v$log_history
where 1=1
-- and first_time > sysdate - 1
order by first_time, minutes;
---检查lgwr i/o性能 (time_waited/total_waits：表示平均lgwr写入完成时间 若>1(百分之一秒)表示写入过慢)
select total_waits,
time_waited,
average_wait,
time_waited / total_waits as avg_time
from v$system_event
where event = 'log file parallel write';
---检查与redo相关性能指标
select name,value from v$sysstat where name like '%redo%';
---查询redo block size
select max(lebsz) from x$kccle;
---查看redo allocation latch
col name for a30
select name, gets, misses, misses / gets
from v$latch
where name = 'redo allocation';
col name for a30
select name, gets, misses, misses / gets
from v$latch_children
where name = 'redo allocation';
---查看与redo相关等待事件
col event format a40
select event,total_waits,time_waited ,total_timeouts,average_wait
from v$system_event
where upper(event) like'%REDO%';
---查看user commit次数
select to_number(value,99999999999) from v$sysstat where name='user commits';
---查看系统运行时间
select (sysdate - startup_time)*24*60*60 as seconds from v$instance
---计算出每秒用户提交次数
selectuser_commit次数/系统运行时间from dual;
---计算出每个事务平均处理多少个redo block
select a.redoblocks / b.trancount
from (select value redoblocks
from v$sysstat
where name = 'redo blocks written') a,
(select value trancount from v$sysstat where name = 'user commits') b
总体配置
---检查database基本信息
select * from v$version;
select name ,open_mode,log_mode from v$database;
--检查是否为rac 实例数量
select instance_number,instance_name ,status from gv$instance;
show parameter cpu_count
--默认数据块大小
show parameter block_size
--各种文件数量
select count(*) from v$controlfile
select count(*) from v$tempfile;
select count(*) from v$datafile;
--资源限制
SELECT * FROM V$RESOURCE_LIMIt ;
--数据库安装信息
SELECT *
FROM V$OPTION
--数据库参数
show parameter
数据文件与空间类
--各种文件数量
select count(*) from v$tempfile;
select count(*) from v$datafile;
--表空间大小
select tablespace_name , sum(bytes)/1024/1024 M from dba_temp_files group by tablespace_name
union all
select tablespace_name , sum(bytes)/1024/1024 M from dba_data_files group by tablespace_name;
--数据文件状态
selectt.online_status,count(*)
from dba_data_filest
group byt.online_status ;
--表空间基本信息
SELECT t.status,
t.tablespace_name,
t.extent_management,
t.segment_space_management,
t.contents
FROM DBA_TABLESPACESt
order by t.status
--临时段使用情况
COL username FORMAT a10;
COL segtype FORMAT a10;
SELECT username,
segtype,
extents "Extents Allocated",
blocks "Blocks Allocated"
FROM v$tempseg_usage;
--查看临时表空间总体使用情况
SELECT TMP_TBS.TABLESPACE_NAME,
SUM(TMP_TBS.TOTAL_MB) TOTAL_MB,
SUM(USED_TOT.USED_MB) USED_MB,
SUM(USED_TOT.USED_MB) / SUM(TMP_TBS.TOTAL_MB) * 100 USED_PERSENT
FROM (SELECT TABLESPACE_NAME, SUM(BYTES) / 1024 / 1024 TOTAL_MB
FROM DBA_TEMP_FILES
GROUP BY TABLESPACE_NAME) TMP_TBS,
(SELECT TMP_USED.TABLESPACE,
SUM(TMP_USED.BLOCKS * PARA.DB_BLOCK_SIZE) / 1024 / 1024 USED_MB
FROM V$SORT_USAGE TMP_USED,
(SELECT VALUE DB_BLOCK_SIZE
FROM V$PARAMETER
WHERE NAME = 'db_block_size') PARA
GROUP BY TMP_USED.TABLESPACE) USED_TOT
where TMP_TBS.TABLESPACE_NAME = USED_TOT.TABLESPACE(+)
GROUP BY TMP_TBS.TABLESPACE_NAME;
--查看临时表空间中排序段和数据段的使用情况
SELECT TMP_TBS.TABLESPACE_NAME, USED_TOT.SEGTYPE TEMP_SEG_TYPE,
SUM(TMP_TBS.TOTAL_MB) TOTAL_MB,
SUM(USED_TOT.USED_MB) USED_MB,
SUM(USED_TOT.USED_MB) / SUM(TMP_TBS.TOTAL_MB) * 100 USED_PERSENT
FROM (SELECT TABLESPACE_NAME, SUM(BYTES) / 1024 / 1024 TOTAL_MB
FROM DBA_TEMP_FILES
GROUP BY TABLESPACE_NAME) TMP_TBS,
(SELECT TMP_USED.TABLESPACE, TMP_USED.SEGTYPE,
SUM(TMP_USED.BLOCKS * PARA.DB_BLOCK_SIZE) / 1024 / 1024 USED_MB
FROM V$SORT_USAGE TMP_USED,
(SELECT VALUE DB_BLOCK_SIZE
FROM V$PARAMETER
WHERE NAME = 'db_block_size') PARA
GROUP BY TMP_USED.TABLESPACE, TMP_USED.SEGTYPE) USED_TOT
where TMP_TBS.TABLESPACE_NAME = USED_TOT.TABLESPACE(+)
GROUP BY TMP_TBS.TABLESPACE_NAME, USED_TOT.SEGTYPE;
--表空间
set linesize 200;
col TABLESPACE_NAMEfor a30;
select a.TABLESPACE_NAME tbs_name,
round(a.BYTES/1024/1024) Total_MB,
round((a.BYTES-nvl(b.BYTES, 0)) /1024/1024) Used_MB,
round((1-((a.BYTES-nvl(b.BYTES,0))/a.BYTES))*100,2) Pct_Free,
nvl(round(b.BYTES/1024/1024), 0) Free_MB ,
auto
from (select TABLESPACE_NAME,
sum(BYTES) BYTES,
max(AUTOEXTENSIBLE) AUTO
from sys.dba_data_files
group by TABLESPACE_NAME) a,
(select TABLESPACE_NAME,
sum(BYTES) BYTES
from sys.dba_free_space
group by TABLESPACE_NAME) b
wherea.TABLESPACE_NAME = b.TABLESPACE_NAME (+)
orderby ((a.BYTES-b.BYTES)/a.BYTES) desc
/
---查看数据文件物理IO信息
SELECT fs.phyrds "Reads",
fs.phywrts"Writes",
fs.avgiotim "Average I/O Time",
df.name "Datafile"
FROM v$datafile df, v$filestat fs
WHERE df.file# = fs.file#
/
--查看所有数据文件i/o情况
/*COL ts FORMAT a10 HEADING "Tablespace";
COL reads FORMAT 999990999;
COL writes FORMAT 999999990;
COL br FORMAT 999999990 HEADING "BlksRead";
COL bw FORMAT 9999999990 HEADING "BlksWrite";
COL rtime FORMAT 9999999990;
COL wtime FORMAT 9999999990;
set linesize 3000;
set pagesize 9999;*/
SELECT ts.name AS ts,
fs.phyrds "Reads",
fs.phywrts "Writes",
fs.phyblkrdAS br,
fs.phyblkwrt AS bw,
fs.readtim/100 "RTime*s",
fs.writetim/100"WTime*s"
FROM v$tablespace ts, v$datafile df, v$filestat fs
WHERE ts.ts# = df.ts#
AND df.file# = fs.file#
UNION
SELECT ts.name AS ts,
ts.phyrds "Reads",
ts.phywrts "Writes",
ts.phyblkrdAS br,
ts.phyblkwrt AS bw,
ts.readtim /100"RTime*s",
ts.writetim/100"WTime*s"
FROM v$tablespace ts, v$tempfile tf, v$tempstat ts
WHERE ts.ts# = tf.ts#
AND tf.file# = ts.file#
ORDER BY 1;
--定位哪些object在buffer cache中存在，占用的buffer cache的量是多少以及占用的是什么类型的buffer cache。
select decode(pd.bp_id,1,'KEEP',2,'RECYCLE',3,'DEFAULT',
4,'2K SUBCACHE',5,'4K SUBCACHE',6,'8K SUBCACHE',
7,'16K SUBCACHE',8,'32KSUBCACHE','UNKNOWN') subcache,
bh.object_name,bh.blocks
from x$kcbwds ds,x$kcbwbpd pd,(select set_ds,
o.name object_name,count(*) BLOCKS
from obj$ o, x$bh x where o.dataobj# = x.obj
and x.state !=0 and o.owner# !=0
group by set_ds,o.name) bh
where ds.set_id >= pd.bp_lo_sid
and ds.set_id <= pd.bp_hi_sid
and pd.bp_size != 0
and ds.addr=bh.set_ds
order bydecode(pd.bp_id,1,'KEEP',2,'RECYCLE',3,'DEFAULT',
4,'2K SUBCACHE',5,'4K SUBCACHE',6,'8K SUBCACHE',
7,'16K SUBCACHE',8,'32KSUBCACHE','UNKNOWN'),bh.blocks;
--针对不同用户的占用buffer的合计
select decode(pd.bp_id,1,'KEEP',2,'RECYCLE',3,'DEFAULT',
4,'2K SUBCACHE',5,'4K SUBCACHE',6,'8K SUBCACHE',
7,'16K SUBCACHE',8,'32KSUBCACHE','UNKNOWN') subcache,
own,sum(bh.blocks)*8192/1024/1024used_M
from x$kcbwds ds,x$kcbwbpd pd,(select set_ds,
o.name object_name,count(*) BLOCKS,u.name own
from obj$ o, x$bh x,user$ u where o.dataobj# = x.obj
and x.state !=0 and o.owner# !=0 and o.owner#=u.user#
group by set_ds,o.name,u.name) bh
where ds.set_id >= pd.bp_lo_sid
and ds.set_id <= pd.bp_hi_sid
And pd.bp_size != 0
and ds.addr=bh.set_ds
group by decode(pd.bp_id,1,'KEEP',2,'RECYCLE',3,'DEFAULT',
4,'2K SUBCACHE',5,'4K SUBCACHE',6,'8K SUBCACHE',
7,'16K SUBCACHE',8,'32KSUBCACHE','UNKNOWN'),
own
orderby own;
--buffer cache 对象所有者，名称， 类型，总大小，cache大小
column c1 heading "Object|Name" format a30 truncate
column c2 heading "Object|Type" format a12 truncate
column c3 heading "Number of|Blocks" format 999,999,999,999
column c4 heading "Percentage|of object|data blocks|in Buffer" format 999
break on report
compute sum of c3 on report
select owner,
object_name,
object_type,
num_blocks,
sum(blocks),
trunc((num_blocks / decode(sum(blocks), 0, .001, sum(blocks))), 4) * 100 || '%' -- buffer中的数据块比例
from (select o.owner owner_name,
o.object_name object_name,
o.object_type object_type,
count(1) num_blocks
from dba_objects o, v$bh bh
where o.object_id = bh.objd
and o.owner not in ('SYS', 'SYSTEM')
group by o.object_name, o.object_type, o.owner
order by count(1) desc) t1,
dba_segments s
where s.segment_name = t1.object_name
and s.owner = t1.owner_name
and num_blocks > 10
group by object_name, object_type, num_blocks, owner
order by num_blocks desc;
--10个热点对象
col objct_name for a30
select * from
(select
ob.owner, ob.object_name, sum(b.tch) Touchs
from x$bh b , dba_objects ob
where b.obj = ob.data_object_id
and b.ts# > 0
group by ob.owner, ob.object_name
order by sum(tch) desc)
where rownum <=10
/
--逻辑读
col objct_name for a30
select *
from (select owner, object_name, value
from v$segment_statistics
where statistic_name = 'logical reads'
order by value desc)
where rownum <= 10
/
--物理读最多十个对象
col objct_name for a30
select *
from (select owner, object_name, value
from v$segment_statistics
where statistic_name = 'physical reads'
order by value desc)
where rownum <= 10
/
---查看热点数据文件(从单块读取时间判断)
COL FILE_NAME FOR A30
COL TABLESPACE_NAME FOR A20
SELECT T.FILE_NAME,
T.TABLESPACE_NAME,
ROUND(S.SINGLEBLKRDTIM / S.SINGLEBLKRDS, 2) AS CS,
S.READTIM/100 READTIME_S,
S.WRITETIM/100 WIRTETIME_S
FROM V$FILESTAT S, DBA_DATA_FILES T
WHERE S.FILE# = T.FILE_ID
AND ROWNUM <= 10
ORDER BY CS DESC
/
undo 与回滚段
---检查undo
show parameter undo_
---检查undo rollback segment 使用情况
select name, rssize, extents, latch, xacts, writes, gets, waits
from v$rollstat a, v$rollname b
where a.usn = b.usn
order by waits desc;
---每个事务产生的redo 块大小
select a.redoblocks / b.trancount
from (select value redoblocks
from v$sysstat
where name = 'redo blocks written') a,
(select value trancount from v$sysstat where name = 'user commits') b;
---计算每秒钟产生的undoblk数量
select sum(undoblks) / sum((end_time - begin_time) * 24 * 60 * 60)
from v$undostat;
---查询undo具体信息
COL undob FORMAT 99990;
COL trans FORMAT 99990;
COL snapshot2old FORMAT 9999999990;
SELECT t.BEGIN_TIME BEGIN_TIME,
t.END_TIME END_TIME,
undoblks "UndoB",
txncount "Trans",
maxquerylen "LongestQuery",
maxconcurrency "MaxConcurrency",
ssolderrcnt "Snapshot2Old",
nospaceerrcnt"FreeSpaceWait"
FROM v$undostat t;
--查询rollback 段详细信息(收缩次数,扩展次数,平均活动事务等)
--COL RBS FORMAT a4;
SELECT n.name "RBS",
s.extends "Extends",
s.shrinks "Shrinks",
s.wraps "Wraps",
s.aveshrink "AveShrink",
s.aveactive "AveActive"
FROM v$rollname n
JOIN v$rollstat s
USING (usn)
WHERE n.name != 'SYSTEM';
---查询当前rollback segment使用情况
COL RBS FORMAT a4;
SELECT n.name "RBS",
s.status,
s.waits,
s.gets,
s.writes,
s.xacts "Active Trans"
FROM v$rollname n
JOIN v$rollstat s
USING (usn)
WHERE n.name != 'SYSTEM';
---查询使用rollback segment时等待比率
SELECT ROUND(SUM(waits/gets)*100,2)||'%' "Contention" FROM
v$rollstat; :):):):)参考学习一下 :)厉害！参考学习一下！ 厉害！参考学习一下！ 受教了、、、 谢谢楼主分享。