直接阅读&在内存数据库中 [英] Direct reads & In memory Database
问题描述
亲爱的，
我们的数据库（DB2 Workgroup 7.2 FP12）经常处于高负荷状态。
大部分时间CPU使用率（1 Pentium3 1Ghz）是更多50％忙。
我们有3GB RAM内存
我们的正常工作量是200-300 dyn.sql / s。
行动问题是否有消除直接I / O的方法？
根据定义，直接I / O是绕过缓冲池并用于
LONG VARCHAR和LOB的I / O数据。
但是系统目录表中有很多LONG VARCHAR。
系统目录的大小是64 MB，所以我想把它全部放在RAM中
记忆
这可能吗？
提前致谢，
Oleg
Dear all,
Our database (DB2 Workgroup 7.2 FP12) is constantly under heavy load.
Most time CPU usage (1 Pentium3 1Ghz) is more 50% busy.
We have 3GB RAM memory
Our normal workload is 200-300 dyn.sql/s.
The action question is there way to eliminate direct I/O?
By definition direct I/O is I/O that bypass bufferpools and used for
LONG VARCHAR and LOBs data.
But there a lot of LONG VARCHARs in system catalog tables.
size of system catalog is 64 mb so i want to place it all in RAM
memory
Is this possible?
Thanks in advance,
Oleg
推荐答案
Alex Greem写道：
Alex Greem wrote:
亲爱的，
我们的数据库（DB2 Workgroup 7.2 FP12）经常负载很重。
大部分时间CPU使用率（1 Pentium3 1Ghz）比较忙50％。
我们有3GB RAM内存
O你的正常工作量是200-300 dyn.sql / s。
行动问题是否有消除直接I / O的方法？
根据定义，直接I / O是旁路的I / O缓冲池并用于LONG VARCHAR和LOB数据。
但是系统目录表中有很多LONG VARCHAR。
系统目录的大小是64 MB，所以我想把它全部放在RAM中
内存
这可能吗？
提前致谢，
Oleg
Dear all,
Our database (DB2 Workgroup 7.2 FP12) is constantly under heavy load.
Most time CPU usage (1 Pentium3 1Ghz) is more 50% busy.
We have 3GB RAM memory
Our normal workload is 200-300 dyn.sql/s.
The action question is there way to eliminate direct I/O?
By definition direct I/O is I/O that bypass bufferpools and used for
LONG VARCHAR and LOBs data.
But there a lot of LONG VARCHARs in system catalog tables.
size of system catalog is 64 mb so i want to place it all in RAM
memory
Is this possible?
Thanks in advance,
Oleg
什么是目录缓存命中率？您的直接读取是否全部在SYSCATSPACE上占据
，或者它们是否也出现在其他表空间中？
----- =通过新闻源发布。 Com，Uncensored Usenet News = -----
http://www.newsfeeds.com - 世界排名第一的新闻组服务！
----- ==超过100,000个新闻组--19个不同的服务器！ = -----
What''s the catalog cache hit ratio? Are your direct reads all taking
place on SYSCATSPACE, or are they occurring in other tablespaces, too?
-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 100,000 Newsgroups - 19 Different Servers! =-----
Ian< ia ***** @ mobileaudio.com>在消息新闻中写道：< 40 ******** @ corp.newsgroups.com> ...
Ian <ia*****@mobileaudio.com> wrote in message news:<40********@corp.newsgroups.com>...
什么是目录缓存命中率？您的直接读取是否全部在SYSCATSPACE上，或者它们是否也出现在其他表空间中？
What''s the catalog cache hit ratio? Are your direct reads all taking
place on SYSCATSPACE, or are they occurring in other tablespaces, too?
SYSCATSPACE的缓冲池命中率为99.99。
大多数直接读取发生在SYSCATSPACE中。
约1000000（syscatspace）vs 10000（其他表空间）
我怀疑这是因为dinamyc sqls，我们有许多SQL函数
（他们的bodys存储在目录中的LONG VARCHAR列中），视图等...
所以我的意图是消除直接i / o尽可能多。
SYSCATSPACE have 99.99 bufferpool hit ratio.
Most of direct reads happens in SYSCATSPACE.
approximately 1000000(syscatspace) vs 10000 (other tablespaces)
I suspect this because of dinamyc sqls, we have many SQL functions
(their bodys stored in LONG VARCHAR column in catalog), views, etc...
So my intention is eliminate direct i/o as much is possible.
如果看一下如何在DB2中处理LONGVACHAR，它将永远是由直接I / O处理的
和因此永远不会去缓冲池。所以，
在私有syscat.spce缓冲池中加载所有syscatcpace表
不是正确的方法。
有''在bp'中加载LONGVARCHAR是没有意义的，因为它们会泛滥bp
并影响所有其他应用程序。
因此，他们可以按需逐个检索，到应用程序。私人
请求他们的代理人的记忆。从pwe中的页面中读取指针，然后使用
指针直接检索数据，读取文件并输入长数据申请私人
memoty。
HTH，皮埃尔。
Alex Greem写道：
If one looks at how LONGVACHAR is handled in DB2, it will always be
handled by direct I/O and thus will NEVER go to a buffer pool. So,
loading all syscatcpace tables in a private syscat.spce buffer pool
wouldn''t be the right approach.
There''s no sense to load LONGVARCHAR in bp''s as they would flood the bp
and impact all other apps.
They are therefore retrieved one by one, on demand, to the appl. private
memory of the agent requesting them. Thepointer is read from the row in
the page in thwe bp but the data is directly retrieved, using the
pointer, by reading the file and the long data is put in appl. private
memoty.
HTH, Pierre.
Alex Greem wrote:
Ian< ia ***** @ mobileaudio.com>在消息新闻中写道：< 40 ******** @ corp.newsgroups.com> ...
Ian <ia*****@mobileaudio.com> wrote in message news:<40********@corp.newsgroups.com>...
什么是目录缓存命中率？您的直接读取是否全部放在SYSCATSPACE上，或者它们是否也出现在其他表空间中？
What''s the catalog cache hit ratio? Are your direct reads all taking
place on SYSCATSPACE, or are they occurring in other tablespaces, too?
SYSCATSPACE有99.99缓冲池命中率。
大多数直接读取读取发生在SYSCATSPACE。
大约1000000（syscatspace）vs 10000（其他表空间）
我怀疑这是因为dinamyc sqls，我们有很多SQL函数
（他们的bodys存储在LONG VARCHAR列中目录），视图等...
所以我的意图是尽可能消除直接i / o。
SYSCATSPACE have 99.99 bufferpool hit ratio.
Most of direct reads happens in SYSCATSPACE.
approximately 1000000(syscatspace) vs 10000 (other tablespaces)
I suspect this because of dinamyc sqls, we have many SQL functions
(their bodys stored in LONG VARCHAR column in catalog), views, etc...
So my intention is eliminate direct i/o as much is possible.
-
Pierre Saint-Jacques - 回复：sesconsjunk at attglobaljunk dot com
重建地址：删除两个垃圾并替换at和dot by
他们的符号。
IBM DB2 Cerified解决方案专家 - 管理
SES顾问公司
--
Pierre Saint-Jacques - Reply to: sesconsjunk at attglobaljunk dot com
Reconstruct address: Remove the two junk and replace at and dot by
their symbols.
IBM DB2 Cerified Solutions Expert - Administration
SES Consultants Inc.
这篇关于直接阅读&在内存数据库中的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
