Comments on: A quick survey of data warehouse management technology http://www.dbms2.com/2007/12/14/data-warehouse-database-management/ Choices in data management and analysis Fri, 16 May 2008 07:40:00 +0000 http://wordpress.org/?v=2.5 By: DBMS2 — DataBase Management System Services » Blog Archive » Positioning the data warehouse appliances and specialty DBMS http://www.dbms2.com/2007/12/14/data-warehouse-database-management/#comment-82948 DBMS2 — DataBase Management System Services » Blog Archive » Positioning the data warehouse appliances and specialty DBMS Fri, 25 Apr 2008 04:11:37 +0000 http://www.dbms2.com/2007/12/14/data-warehouse-database-management/#comment-82948 [...] A quick survey of data warehouse management technology [...] […] A quick survey of data warehouse management technology […]

]]> By: Curt Monash http://www.dbms2.com/2007/12/14/data-warehouse-database-management/#comment-74743 Curt Monash Tue, 26 Feb 2008 22:01:37 +0000 http://www.dbms2.com/2007/12/14/data-warehouse-database-management/#comment-74743 DB2 absolutely sounds like it has a good architecture. I don't know what their problem is either. Perhaps, as in the special case of Viper, the practical implementation doesn't live up to theory? I would take issue with you on one thing -- DB2 rightfully competes BOTH with Teradata and Oracle. CAM DB2 absolutely sounds like it has a good architecture. I don’t know what their problem is either. Perhaps, as in the special case of Viper, the practical implementation doesn’t live up to theory?

I would take issue with you on one thing — DB2 rightfully competes BOTH with Teradata and Oracle.

CAM

]]> By: MMIT http://www.dbms2.com/2007/12/14/data-warehouse-database-management/#comment-74701 MMIT Tue, 26 Feb 2008 17:43:17 +0000 http://www.dbms2.com/2007/12/14/data-warehouse-database-management/#comment-74701 Hi: I have worked pretty extensively with DB2 ESE/EEE, and somewhat with both Greenplum and WX2. The later two are marketting themselves as high end data warehouse MPP databases. Can anyone of you please explain me why they are superior to db2? I do not see any difference in their architecture! All three are MPPs. One of them is a very proven software, another runs on postgress, and the third is home made. Performance wise, no one would be able to beat DB2 as they run on P series hardware, and power 6 cpus running at 4 GHz I am wondering why IBM cannot position db2 as a competitor of Teradata and why they are going after Oracle. Thanks Hi:
I have worked pretty extensively with DB2 ESE/EEE, and somewhat with both Greenplum and WX2. The later two are marketting themselves as high end data warehouse MPP databases. Can anyone of you please explain me
why they are superior to db2? I do not see any difference in their architecture! All three are MPPs. One of them is a very proven software, another runs on postgress, and the third is home made.

Performance wise, no one would be able to beat DB2 as they run on P series hardware, and power 6 cpus running at 4 GHz

I am wondering why IBM cannot position db2 as a competitor of Teradata and why they are going after Oracle.
Thanks

]]> By: Curt Monash http://www.dbms2.com/2007/12/14/data-warehouse-database-management/#comment-67223 Curt Monash Wed, 09 Jan 2008 06:22:29 +0000 http://www.dbms2.com/2007/12/14/data-warehouse-database-management/#comment-67223 1. My confusion was to remember the bitmaps and think that Kognitio was actually a column store. In part, it's a distinction without a difference. Bitmaps have the same updating issues column stores do. 2. "Compression" in bitmaps comes into play in at least two ways. One is sparsity. In a naive bitmap, if the cardinality of a column is N, then 1/N of the entries will be 1 and (N-1)/N of them will be 0. That's food for sparsity compression. Second, that's not how bitmaps really are implemented. If cardinality is 1024, there aren't 1024 columns of bits implemented. Rather, numbers are assigned from 0 to 1023, and those are represented in 10 columns of bits. I.e., bitmaps and dictionary/tokenized compression are pretty much the same thing these days, with "bitmap" being a somewhat antiquated term. CAM 1. My confusion was to remember the bitmaps and think that Kognitio was actually a column store. In part, it’s a distinction without a difference. Bitmaps have the same updating issues column stores do.

2. “Compression” in bitmaps comes into play in at least two ways. One is sparsity. In a naive bitmap, if the cardinality of a column is N, then 1/N of the entries will be 1 and (N-1)/N of them will be 0. That’s food for sparsity compression.

Second, that’s not how bitmaps really are implemented. If cardinality is 1024, there aren’t 1024 columns of bits implemented. Rather, numbers are assigned from 0 to 1023, and those are represented in 10 columns of bits. I.e., bitmaps and dictionary/tokenized compression are pretty much the same thing these days, with “bitmap” being a somewhat antiquated term.

CAM

]]> By: Seth Grimes http://www.dbms2.com/2007/12/14/data-warehouse-database-management/#comment-67206 Seth Grimes Wed, 09 Jan 2008 00:37:19 +0000 http://www.dbms2.com/2007/12/14/data-warehouse-database-management/#comment-67206 Curt, with regard to "compressed bitmaps," and not knowing much about Kognitio, two things: - Why bother to compress a bitmap? It's already compact, and I'd think that the overhead in compression/decompression wouldn't be worth the space savings. - I believe that column stores typically don't rely on indexes. That's one reason they have fast load times. Curt, with regard to “compressed bitmaps,” and not knowing much about Kognitio, two things:

- Why bother to compress a bitmap? It’s already compact, and I’d think that the overhead in compression/decompression wouldn’t be worth the space savings.

- I believe that column stores typically don’t rely on indexes. That’s one reason they have fast load times.

]]> By: Curt Monash http://www.dbms2.com/2007/12/14/data-warehouse-database-management/#comment-65247 Curt Monash Sun, 23 Dec 2007 22:32:54 +0000 http://www.dbms2.com/2007/12/14/data-warehouse-database-management/#comment-65247 Wait a moment -- was I also wrong when I wrote that Kognitio "relies on compressed bitmaps" for data access? CAM Wait a moment — was I also wrong when I wrote that Kognitio “relies on compressed bitmaps” for data access?

CAM

]]> By: Curt Monash http://www.dbms2.com/2007/12/14/data-warehouse-database-management/#comment-64098 Curt Monash Fri, 14 Dec 2007 20:00:08 +0000 http://www.dbms2.com/2007/12/14/data-warehouse-database-management/#comment-64098 Fair enough. I didn't say what I could or should about DB2. DB2 mainframe is another shared-everything system. DB2 on open systems -- in practice, that means AIX -- is in theory a solid MPP/shared-nothing system, with the BCUs playing a somewhat appliance-like role. As I said in http://www.dbms2.com/2007/10/05/the-four-horsemen-of-data-warehousing/ and http://www.dbms2.com/2007/10/09/another-firm-that-never-sees-db2-in-data-warehousing/ , it's pretty surprising how little data warehouse traction DB2 has, given DB2's architecture as per http://www.dbms2.com/2006/10/03/ibm-and-teradata-too/ . My comments about the Gartner MQ are summed up in http://www.dbms2.com/2007/10/19/gartner-2007-magic-quadrant-for-data-warehouse-database-management-systems/ (2007) and http://www.dbms2.com/2006/10/03/vendor-segmentation-for-data-warehouse-dbms/ (2006). CAM Fair enough. I didn’t say what I could or should about DB2. DB2 mainframe is another shared-everything system. DB2 on open systems — in practice, that means AIX — is in theory a solid MPP/shared-nothing system, with the BCUs playing a somewhat appliance-like role.

As I said in http://www.dbms2.com/2007/10/05/the-four-horsemen-of-data-warehousing/ and http://www.dbms2.com/2007/10/09/another-firm-that-never-sees-db2-in-data-warehousing/ , it’s pretty surprising how little data warehouse traction DB2 has, given DB2’s architecture as per http://www.dbms2.com/2006/10/03/ibm-and-teradata-too/ .

My comments about the Gartner MQ are summed up in http://www.dbms2.com/2007/10/19/gartner-2007-magic-quadrant-for-data-warehouse-database-management-systems/ (2007) and http://www.dbms2.com/2006/10/03/vendor-segmentation-for-data-warehouse-dbms/ (2006).

CAM

]]> By: Rich T http://www.dbms2.com/2007/12/14/data-warehouse-database-management/#comment-64093 Rich T Fri, 14 Dec 2007 18:33:12 +0000 http://www.dbms2.com/2007/12/14/data-warehouse-database-management/#comment-64093 No DB2 on AIX! are you serious. Gartner continues to put DB2/AIX at the top right hand corner of their quadrants. No DB2 on AIX! are you serious. Gartner continues to put DB2/AIX at the top right hand corner of their quadrants.

]]> By: Curt Monash http://www.dbms2.com/2007/12/14/data-warehouse-database-management/#comment-64083 Curt Monash Fri, 14 Dec 2007 16:34:35 +0000 http://www.dbms2.com/2007/12/14/data-warehouse-database-management/#comment-64083 Oh, crumb. I'm sorry about that. I should have checked my own post from last year. http://www.dbms2.com/2006/10/05/introduction-to-kognitio-wx-2/ CAM Oh, crumb. I’m sorry about that.

I should have checked my own post from last year. http://www.dbms2.com/2006/10/05/introduction-to-kognitio-wx-2/

CAM

]]> By: Paul Groom http://www.dbms2.com/2007/12/14/data-warehouse-database-management/#comment-64081 Paul Groom Fri, 14 Dec 2007 16:18:05 +0000 http://www.dbms2.com/2007/12/14/data-warehouse-database-management/#comment-64081 Curt, Kognitio WX2 (formerly WhiteCross) is a standard row based relational database similar to Netezza, Datallegro, Teradata etc.. The differentiation from these other vendors is that WX2 is a software based product that will run on commodity X86 servers running Linux i.e. a virtual data warehouse appliance. WX2 has always been row based for simplicity (in an MPP architecture) and for high performance scalable loading. Paul Groom Director, Business Intelligence Kognitio Curt, Kognitio WX2 (formerly WhiteCross) is a standard row based relational database similar to Netezza, Datallegro, Teradata etc.. The differentiation from these other vendors is that WX2 is a software based product that will run on commodity X86 servers running Linux i.e. a virtual data warehouse appliance. WX2 has always been row based for simplicity (in an MPP architecture) and for high performance scalable loading.

Paul Groom
Director, Business Intelligence
Kognitio

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