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IBM Cognos 10 Platform => Cognos 10 BI => Dynamic Cubes => Topic started by: Raj on 09 Jun 2015 12:09:24 AM

Title: dynamic query analyser
Post by: Raj on 09 Jun 2015 12:09:24 AM
HI,
  i am new for cubes i have some questions please explain me

what is dynamic query analyser and why we used dynamic query analyser?
what is the difference between DQM and CQM?in which cases we go for DQM and CQM?
what is the difference between power cubes and dynamic cubes?


Thanks,
  sekhar
Title: Re: dynamic query analyser
Post by: MFGF on 09 Jun 2015 04:54:22 AM
Quote from: sekhar1988 on 09 Jun 2015 12:09:24 AM
HI,
  i am new for cubes i have some questions please explain me

what is dynamic query analyser and why we used dynamic query analyser?

Hi.

Take a look at the Dynamic Query Redbook - chapter 7, section 7.4:

http://www.redbooks.ibm.com/redbooks/pdfs/sg248121.pdf

Quote from: sekhar1988 on 09 Jun 2015 12:09:24 AM
what is the difference between DQM and CQM?in which cases we go for DQM and CQM?

CQM is the old Compatible Query Mode engine, written in C++ and with architecture dating back to the days of Cognos PowerHouse (its ancestor used to be called DMS in PowerHouse, then UDA in Impromptu, then CQM in ReportNet/C8/C10). It is 32-bit and runs outside of the java servlet container Cognos 10 BI uses for the rest of its processing.
DQM is Dynamic Query Mode. It is 64-bit and written in java so it runs within the C10 java servlet container. Take a look at Chapter 1 of the Dynamic Query Redbook:

http://www.redbooks.ibm.com/redbooks/pdfs/sg248121.pdf

Quote from: sekhar1988 on 09 Jun 2015 12:09:24 AM
what is the difference between power cubes and dynamic cubes?


Thanks,
  sekhar

That's like asking what is the difference between a domestic cat and a lion. They are both OLAP technologies, but they are entirely different architectures with different sweet spots. PowerCubes are small, agile, can span multiple data sources or be built from csv files, are based on an architecture using files in the filesystem, can be portable, do not scale well to massive data volumes, have limits on numbers of members (catagories) etc. Dynamic Cubes are often large, sit over data warehouses, use in-memory caching at several levels, can utilize in-database aggregate tables or views, are designed to work with data in star or snowflake schemas, are not portable, can not be built over csv files, scale to ENORMOUS volumes of data etc.

Take a look at the Dynamic Cubes Cookbook:

http://www.redbooks.ibm.com/redbooks/pdfs/sg248064.pdf

Cheers!

MF.
Title: Re: dynamic query analyser
Post by: Raj on 09 Jun 2015 05:45:59 AM
Thanks MFGF