Oracle设置Shared Pool的大小

在oracle 10G或者11G版本中，如何合理设置shared pool大小，对oracle数据库的性能影响很大。

Shared Pool的大小设置规则如下：

1.查到shared pool设置的合理值，语句如下：

select 'Shared Pool' component,

shared_pool_size_for_estimate estd_sp_size,

estd_lc_time_saved_factor parse_time_factor,

case

when current_parse_time_elapsed_s + adjustment_s < 0 THEN

0

ELSE

current_parse_time_elapsed_s + adjustment_s

END response_time

FROM (select shared_pool_size_for_estimate,

shared_pool_size_factor,

estd_lc_time_saved_factor,

a.estd_lc_time_saved,

e.VALUE / 100current_parse_time_elapsed_s,

c.estd_lc_time_saved - a.estd_lc_time_saved adjustment_s

from v$shared_pool_advice a,

(select * from v$sysstat where NAME = 'parse time elapsed') e,

(select estd_lc_time_saved

from v$shared_pool_advice

where shared_pool_size_factor = 1) c);

2.设置上个SQL语句中查到的PARSE_TIME_FACTOR首次等于1的记录所在行的ESTD_SP_SIZE的值为shared pool。

3.设置语句如下：

alter system set shared_pool_size=XXX scope=spfile;或者alter system set shared_pool_size=XXX scope=both;