|
7 1 20000 0 1 8000 8000 8000 8000 8000 8000 8000 8000
8 rows selected.
--//SPIN数量不变.实际上动态修改,对应exclusive latch无效.仅仅对shared latch有效,导致实际spin 数量等于_spin_count*2.(我当前没有测试)
--//参考链接:http://andreynikolaev.wordpress.com/2011/01/14/spin-tales-part-2-shared-latches-in-oracle-9-2-11g/
3.测试2:
SYS@book> alter system set "_spin_count"=200 scope=spfile ;
System altered.
--//重启数据库观察:
SYS@book> select * from x$ksllclass ;
ADDR INDX INST_ID SPIN YIELD WAITTIME SLEEP0 SLEEP1 SLEEP2 SLEEP3 SLEEP4 SLEEP5 SLEEP6 SLEEP7
---------------- ---------- ---------- ---------- ---------- ---------- ---------- ---------- ---------- ---------- ---------- ---------- ---------- ----------
00000000861986C0 0 1 200 0 1 8000 8000 8000 8000 8000 8000 8000 8000
00000000861986EC 1 1 200 0 1 1000 1000 1000 1000 1000 1000 1000 1000
0000000086198718 2 1 200 0 |