Google Groups Home
Help | Sign in
about snapshot monitor
There are currently too many topics in this group that display first. To make this topic appear first, remove this option from another topic.
There was an error processing your request. Please try again.
flag
  2 messages - Collapse all
The group you are posting to is a Usenet group. Messages posted to this group will make your email address visible to anyone on the Internet.
Your reply message has not been sent.
Your post was successful
%NAME%  
View profile
 More options May 9, 2:15 pm
Newsgroups: comp.databases.ibm-db2
From: "%NAME%" <huaxinzh...@gmail.com>
Date: Fri, 9 May 2008 11:15:23 -0700 (PDT)
Local: Fri, May 9 2008 2:15 pm
Subject: about snapshot monitor
Hi,

When collecting snapshot, there is seemingly discrepency between query
running time and some metrics collected.

For example, on a DPF with 8 nodes, I have   8863201 seconds for
"Total buffer pool read time (milliseconds)" from running  "db2 get
snapshot for all on bcudb global"

Then without the "global" option, on each node, there is around
1110000 -- 1120000 milisec for the same metric, e.g. "Total buffer
pool read time (milliseconds) = 1119828"

However, the query itself only runs less than 200 seconds, which is
only 1/5  of the time for "total buffer pool read time" on each node.
How could this be? The snapshot before running the query shows close
to 0 seconds, e.g.  "Total buffer pool read time (milliseconds) =
203", so there should be no error.

I guess they multiplied this time with number of prefetchers?

Huaxin


    Reply to author    Forward  
You must Sign in before you can post messages.
To post a message you must first join this group.
Please update your nickname on the subscription settings page before posting.
You do not have the permission required to post.
Udo  
View profile
 More options May 14, 6:34 pm
Newsgroups: comp.databases.ibm-db2
From: Udo <udo.we...@gmail.com>
Date: Wed, 14 May 2008 15:34:11 -0700 (PDT)
Local: Wed, May 14 2008 6:34 pm
Subject: Re: about snapshot monitor

> I guess they multiplied this time with number of prefetchers?

You are right. From the System Monitor Guide:

> At the database and table space levels, this element includes the value of pool_async_read_time. <

see http://publib.boulder.ibm.com/infocenter/db2luw/v8/index.jsp?topic=/c...

Regards,
Udo

--
Speedgain for DB2 - the DB2 monitor
http://www.itgain.de/en/produkte/speedgain.html


    Reply to author    Forward  
You must Sign in before you can post messages.
To post a message you must first join this group.
Please update your nickname on the subscription settings page before posting.
You do not have the permission required to post.
End of messages
« Back to Discussions « Newer topic     Older topic »

Create a group - Google Groups - Google Home - Terms of Service - Privacy Policy
©2008 Google