eygle.com   eygle.com
eygle.com  
 

« 一路向北 | Blog首页 | DBWR enhancements In Oracle10g II »

DBWR enhancements In Oracle10g

作者:eygle |【转载时请以超链接形式标明文章和作者信息及本声明
链接:

为了避免DBWR不必要的唤醒及过于活跃,从Oracle10g开始,Oracle对DBWR的SCAN间隔进行了调整.

在内部由一个隐含参数:_dbwr_scan_interval 控制.

Oracle9i中这个参数缺省值为10 s: 

SQL> select * from v$version
  2  /
BANNER
----------------------------------------------------------------
Oracle9i Enterprise Edition Release 9.2.0.4.0 - 64bit Production
PL/SQL Release 9.2.0.4.0 - Production
CORE    9.2.0.3.0       Production
TNS for Solaris: Version 9.2.0.4.0 - Production
NLSRTL Version 9.2.0.4.0 - Production
SQL> col ksppinm for a20
SQL> col ksppdesc for a40
SQL> col ksppstvl for a10
SQL> select
  2    ksppinm,ksppdesc,ksppstvl
  3  from
  4    sys.x$ksppi x,
  5    sys.x$ksppcv y
  6  where
  7    x.inst_id = userenv('Instance') and
  8    y.inst_id = userenv('Instance') and
  9    x.indx = y.indx and
 10    x.ksppinm like '%_dbwr_scan%'
 11  /
KSPPINM              KSPPDESC                                 KSPPSTVL
-------------------- ---------------------------------------- ----------
_dbwr_scan_interval  dbwriter scan interval                   10 

从Oracle10g开始,此缺省值被调这个为300 s:

SQL> select * from v$version
  2  /
BANNER
----------------------------------------------------------------
Oracle Database 10g Enterprise Edition Release 10.1.0.3.0 - 64bi
PL/SQL Release 10.1.0.3.0 - Production
CORE    10.1.0.3.0      Production
TNS for Solaris: Version 10.1.0.3.0 - Production
NLSRTL Version 10.1.0.3.0 - Production
SQL> col ksppinm for a20
SQL> col ksppdesc for a40
SQL> col ksppstvl for a10
SQL> select
  2    ksppinm,ksppdesc,ksppstvl
  3  from
  4    sys.x$ksppi x,
  5    sys.x$ksppcv y
  6  where
  7    x.inst_id = userenv('Instance') and
  8    y.inst_id = userenv('Instance') and
  9    x.indx = y.indx and
 10    x.ksppinm like '%_dbwr_scan%'
 11  /
KSPPINM              KSPPDESC                                 KSPPSTVL
-------------------- ---------------------------------------- ----------
_dbwr_scan_interval  dbwriter scan interval                   300 

在Oracle10gR2中,这个参数未作进一步调整,缺省值仍然为300:

SQL> select * from v$version
  2  /
BANNER
----------------------------------------------------------------
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Prod
PL/SQL Release 10.2.0.1.0 - Production
CORE    10.2.0.1.0      Production
TNS for Linux: Version 10.2.0.1.0 - Production
NLSRTL Version 10.2.0.1.0 - Production
SQL> col ksppinm for a20
SQL> col ksppdesc for a40
SQL> col ksppstvl for a10
SQL> select
  2    ksppinm,ksppdesc,ksppstvl
  3  from
  4    sys.x$ksppi x,
  5    sys.x$ksppcv y
  6  where
  7    x.inst_id = userenv('Instance') and
  8    y.inst_id = userenv('Instance') and
  9    x.indx = y.indx and
 10    x.ksppinm like '%_dbwr_scan%'
 11  /
KSPPINM              KSPPDESC                                 KSPPSTVL
-------------------- ---------------------------------------- ----------
_dbwr_scan_interval  dbwriter scan interval                   300
 

以上内容,仅供参考.

 


历史上的今天...
      >> 2009-02-07文章:
      >> 2008-02-07文章:
      >> 2007-02-07文章:
             Oracle10g Events CONTROLF的改变
      >> 2005-02-07文章:
             如何获得Oracle的隐含参数
------
这篇 【DBWR enhancements In Oracle10g】来自 eygle.com | CSDN网摘| del.icio.us|Google订阅 | 鲜果订阅 | 抓虾订阅

By eygle on 2006-02-07 16:09 | Comments (0) | Posted to Internal | Oracle10g/11g | Edit |

相关文章 随机文章
  • 20090811-墨墨、书书、Oracle
  • Oracle收购GoldenGate - 甲骨文到底想做什么
  • Oracle 74亿美元购SUN - 彻底改变产业格局
  • TimesTen:Cache Group局部数据缓存及Aging
  • TimesTen 7.0.5 For Linx安装过程记录
  • 游览的勇气 香山归来记
    2PC、XA、DTP与两阶段提交
    黄山云海观日出
    《深入浅出Oracle》更名《深入解析Oracle》
    Oracle的分区表和Local索引创建与维护
    搜索本站:

    留言 (0)

    发表留言:



    Remember Me?
    (输入验证码后方可评论,谢谢支持)



    CopyRight © 2004~2010 eygle.com, All rights reserved.