db_writer_processes默认大小

db_writer_processes是DBWn进程数量的参数，默认=CPU_COUNT/8. 下面在我笔记本上看到的这个参数是=1，一个双核CPU-7250： C:\Users\Administrator>systeminfo ...... ...... 系统制造商: Dell Inc. 系统型号: Vostro 1400 系统类型: X86-based PC 处理器: 安装了 1 个处理器。 [01]: x64 Family 6 Model 15 Stepping 13 GenuineIntel ~2001 Mhz ...... ...... 看到对应的db_writer_processes=1. C:\Users\Administrator>sqlplus /nolog SQL*Plus: Release 10.2.0.1.0 - Production on 星期二 1月 18 15:15:37 2011 Copyright (c) 1982, 2005, Oracle. All rights reserved. idle> conn /as sysdba 已连接。 sys@TEST> show parameter db_writer; NAME TYPE VALUE ------------------------------------ ----------- ------------------------------ db_writer_processes integer 1 下面看到的是另一个环境的参数=2，由于是16核的CPU，所以16/8=2. [oracle@crmdb2 ~]$ cat /proc/cpuinfo | grep name model name : Intel(R) Xeon(R) CPU E7330 @ 2.40GHz model name : Intel(R) Xeon(R) CPU E7330 @ 2.40GHz model name : Intel(R) Xeon(R) CPU E7330 @ 2.40GHz model name : Intel(R) Xeon(R) CPU E7330 @ 2.40GHz model name : Intel(R) Xeon(R) CPU E7330 @ 2.40GHz model name : Intel(R) Xeon(R) CPU E7330 @ 2.40GHz model name : Intel(R) Xeon(R) CPU E7330 @ 2.40GHz model name : Intel(R) Xeon(R) CPU E7330 @ 2.40GHz model name : Intel(R) Xeon(R) CPU E7330 @ 2.40GHz model name : Intel(R) Xeon(R) CPU E7330 @ 2.40GHz model name : Intel(R) Xeon(R) CPU E7330 @ 2.40GHz model name : Intel(R) Xeon(R) CPU E7330 @ 2.40GHz model name : Intel(R) Xeon(R) CPU E7330 @ 2.40GHz model name : Intel(R) Xeon(R) CPU E7330 @ 2.40GHz model name : Intel(R) Xeon(R) CPU E7330 @ 2.40GHz model name : Intel(R) Xeon(R) CPU E7330 @ 2.40GHz [oracle@crmdb2 ~]$ sqlplus /nolog SQL*Plus: Release 10.2.0.3.0 - Production on Tue Jan 18 15:14:05 2011 Copyright (c) 1982, 2006, Oracle. All Rights Reserved. SQL> conn /as sysdba Connected. SQL> show parameter db_writer; NAME TYPE VALUE ------------------------------------ ----------- ------------------------------ db_writer_processes integer 2 SQL> -The End-