oracle statspack实例(二)

最新推荐文章于 2021-04-11 22:46:09 发布

最新推荐文章于 2021-04-11 22:46:09 发布 · 89 阅读

文章标签：

#Oracle #SQL #HP #Cache

本文详细介绍了如何通过查询Oracle数据库的相关视图来评估和调整SGA和PGA内存分配，包括数据缓冲区命中率、排序操作效率及日志缓冲区配置等关键指标的计算方法。

--内存调整

select * from v$sga;

--调整前SGA

NAME VALUE
-------------------- ----------
Fixed Size 452184
Variable Size 402653184
Database Buffers 251658240
Redo Buffers 667648

select * from v$sgastat;

POOL NAME BYTES
----------- -------------------------- ----------
fixed_sga 452184
buffer_cache 251658240
log_buffer 656384
shared pool errors 8940
shared pool enqueue 171860
shared pool KGK heap 3756
shared pool KQR M PO 1393788
shared pool KQR S PO 177272
shared pool KQR S SO 5120
shared pool sessions 410040
shared pool sql area 61446860

POOL NAME BYTES
----------- -------------------------- ----------
shared pool 1M buffer 2098176
shared pool KGLS heap 2613480
shared pool PX subheap 19684
shared pool parameters 39012
shared pool free memory 125812664
shared pool PL/SQL DIANA 3445584
shared pool FileOpenBlock 695504
shared pool PL/SQL MPCODE 637644
shared pool PL/SQL PPCODE 48400
shared pool PL/SQL SOURCE 14344
shared pool library cache 19376952

POOL NAME BYTES
----------- -------------------------- ----------
shared pool miscellaneous 8639216
shared pool PLS non-lib hp 2068
shared pool joxs heap init 4220
shared pool table definiti 2632
shared pool trigger defini 1128
shared pool trigger inform 528
shared pool trigger source 624
shared pool Checkpoint queue 564608
shared pool VIRTUAL CIRCUITS 265160
shared pool dictionary cache 1614976
shared pool KSXR receive buffers 1032500

POOL NAME BYTES
----------- -------------------------- ----------
shared pool character set object 432136
shared pool FileIdentificatonBlock 319452
shared pool message pool freequeue 833032
shared pool KSXR pending messages que 840636
shared pool event statistics per sess 1908760
shared pool fixed allocation callback 268
large pool free memory 83886080
java pool free memory 83886080

41 rows selected.

--UGA的大小,UGA主要包含一下部分的内存设置

show parameters area_size;

NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
bitmap_merge_area_size integer 1048576
create_bitmap_area_size integer 8388608
hash_area_size integer 1048576
sort_area_size integer 524288
workarea_size_policy string AUTO

--计算数据缓冲区命中率

select value from v$sysstat where name='physical reads' 4383475

select * from v$sysstat where name='physical reads direct' 3834798

select * from v$sysstat where name='physical reads direct (lob)' 374616

select * from v$sysstat where name like 'consistent gets' 1198738167

select * from v$sysstat where name like 'db block gets' 53472785

x=physical reads direct+physical reads direct (lob)

100-(physical reads-x)/(consistent gets+db block gets-x)*100

100-(4383475-3834798-374616)/(1198738167+53472785-3834798-374616)*100

--共享池的命中率
select sum(pinhits)/sum(pins)*100 "hit radio" from v$librarycache;

--关于排序部分

select name,value from v$sysstat where name like '%sort%';