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分类： oracle
2011-03-16 09:40:42
测试cache对sequence的影响。
环境：
oracle 10.2.0.3.0 rac
两台小机 4c 8g
oracle 10.2.0.3.0 rac
两台小机 4c 8g
测试 开两个窗口 多次同时执行取平均值
create sequence sno nocache; -- 1分.03
create sequence s20 cache 20; -- 2.08 秒
create sequence s100 cache 100; -- .04
create sequence s1000 cache 1000; -- .03
create sequence s20 cache 20; -- 2.08 秒
create sequence s100 cache 100; -- .04
create sequence s1000 cache 1000; -- .03
create sequence snor nocache order ; -- 1分.03
create sequence s20r cache 20 order; -- 4.06
create sequence s100r cache 100 order; -- 2.02
create sequence s1000r cache 1000 order; -- 2.00
create sequence s20r cache 20 order; -- 4.06
create sequence s100r cache 100 order; -- 2.02
create sequence s1000r cache 1000 order; -- 2.00
------------
挨个执行
declare
n number;
begin
for i in 0..10000 loop
select s1000r.nextval into n from dual;
end loop;
end;
/
declare
n number;
begin
for i in 0..10000 loop
select s1000r.nextval into n from dual;
end loop;
end;
/
------------
清理
drop sequence sno;
drop sequence s20;
drop sequence s100;
drop sequence s1000;
drop sequence s20;
drop sequence s100;
drop sequence s1000;
drop sequence snor;
drop sequence s20r;
drop sequence s100r;
drop sequence s1000r;
drop sequence s20r;
drop sequence s100r;
drop sequence s1000r;
结论：创建sequence时用cache 100 order ，速度与原先的cache 20相当，而且解决避免rac环境中的不顺序生成问题。
给主人留下些什么吧！~~
