Author Topic: Buffer file during a query on Query Studio  (Read 3031 times)

Offline rafhael_d

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Buffer file during a query on Query Studio
« on: 10 Aug 2012 03:03:59 pm »
Hi everyone,

I know that in Cognos 7, the application creates a buffer file when some query is executed. These files were nominated as "uda[numbers]" without extension. For example, "uda13445140350".

I want to know if there is any buffer file like that in cognos 8 and where does it is created.

Thanks in advance.

Offline rafhael_d

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Re: Buffer file during a query on Query Studio
« Reply #1 on: 14 Aug 2012 07:28:36 am »
I found some configuration in Framework manager about Allow usage of local cache. This option ticked to true makes that "all reports based on this model will use cached data. This setting affects all reports that use this model."

Ok, I understand the purpose of this file with cached data. At second query, the consult speed will increase a lot.
But I need to understand how this file is created, to try to increase this performance, like redirect it to dedicated partition, etc.
At cognos 7, I watched cached files created with 2 gigabytes. And this operation consumes many resources of my server.

I'm trying to track transactions between Cognos BI Server and Oracle during a query on Connection (in a third machine) and track information transfered to this third machine.
And I notice that the data transfered from Oracle to BI Server are taking +-15 seconds (in most heavy queries). Then, Oracle sends information to BI, during about 10 seconds. After that, I capture high Hard Disk writing events.
Then, +- 4 minutes after that, Cognos Query Studio shows infomation that I requested.

If anyone experienced a issue on this configuration, please, give me some tips or explanation =]
Thanks in advance.

Offline rafhael_d

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Re: Buffer file during a query on Query Studio
« Reply #2 on: 12 Sep 2012 07:21:58 am »
Hope this helps someone who's finding related information.

I've received a response from IBM support which explained me about this issues.
In resume, Cognos (7 to 8.4.1) decides how to process cache information. If it needs cache and if it will write this cached file or not, the final decision is delegated to Cognos. Independs what configuration you have setup on Framework Manager (Allow usage of local cache), Cognos will override this configuration if it need.
This configuration is not a rule, it's only a "preference". If Cognos needs to write this file, it will write, doesn't matter what you have setup.
Also, the IBM Analyst told me that only in version 10.2, which hasn't been released yet, this type of configuration can be really controlled.

And yes, i've searched in many documents and forums about this issue, but didn't brought me information i needed.

 


       
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