Comments on: Drilling Down in the Oracle Next-Generation Reference DW Architecture http://www.rittmanmead.com/2009/07/16/drilling-down-in-the-oracle-next-generation-reference-dw-architecture/ Delivered Intelligence Wed, 17 Mar 2010 13:47:41 -0400 http://wordpress.org/?v=2.8.4 hourly 1 By: Dhrubo http://www.rittmanmead.com/2009/07/16/drilling-down-in-the-oracle-next-generation-reference-dw-architecture/comment-page-1/#comment-10317 Dhrubo Mon, 20 Jul 2009 11:14:19 +0000 http://www.rittmanmead.com/2009/07/16/drilling-down-in-the-oracle-next-generation-reference-dw-architecture/#comment-10317 Gud one Mark, Ya this does work gud..and Simon Griffith had given us some valuable inputs going ahead to this design about 3yrs back and now we see it was worth moving with this Architecture. Gud one Mark,
Ya this does work gud..and Simon Griffith had given us some valuable inputs going ahead to this design about 3yrs back and now we see it was worth moving with this Architecture.

]]> By: Sid http://www.rittmanmead.com/2009/07/16/drilling-down-in-the-oracle-next-generation-reference-dw-architecture/comment-page-1/#comment-10291 Sid Fri, 17 Jul 2009 19:38:16 +0000 http://www.rittmanmead.com/2009/07/16/drilling-down-in-the-oracle-next-generation-reference-dw-architecture/#comment-10291 Mark, while I can agree with you on the fact that not everything is a dimension query and incorporating large changes into a dimension model in short period of time is tricky, I am a bit skeptic about the selling point of the foundation layer. A compelling real life example would be helpful. Also, foundation layer has to contain both entities and relationships in some form. And should not this reference architecture contain some mechanism for storing accessing and updating the meta data? Mark,
while I can agree with you on the fact that not everything is a dimension query and incorporating large changes into a dimension model in short period of time is tricky, I am a bit skeptic about the selling point of the foundation layer. A compelling real life example would be helpful. Also, foundation layer has to contain both entities and relationships in some form. And should not this reference architecture contain some mechanism for storing accessing and updating the meta data?

]]> By: Mark Rittman http://www.rittmanmead.com/2009/07/16/drilling-down-in-the-oracle-next-generation-reference-dw-architecture/comment-page-1/#comment-10284 Mark Rittman Fri, 17 Jul 2009 07:51:58 +0000 http://www.rittmanmead.com/2009/07/16/drilling-down-in-the-oracle-next-generation-reference-dw-architecture/#comment-10284 Jeff, I guess it's a semantic thing - you've got to model history in the foundation layer some how, and start and end-dating the changed records is of course one way. I would steer clear of surrogate keys in this level though, and try and make sure what we're tracking changes on are entities, not dimensions - it's the dimensional modeling but I'm trying to get away from in this level, in favour of analysis-neutral entities. regards, Mark Jeff,

I guess it’s a semantic thing – you’ve got to model history in the foundation layer some how, and start and end-dating the changed records is of course one way. I would steer clear of surrogate keys in this level though, and try and make sure what we’re tracking changes on are entities, not dimensions – it’s the dimensional modeling but I’m trying to get away from in this level, in favour of analysis-neutral entities.

regards, Mark

]]> By: Jeff Moss http://www.rittmanmead.com/2009/07/16/drilling-down-in-the-oracle-next-generation-reference-dw-architecture/comment-page-1/#comment-10281 Jeff Moss Fri, 17 Jul 2009 07:22:20 +0000 http://www.rittmanmead.com/2009/07/16/drilling-down-in-the-oracle-next-generation-reference-dw-architecture/#comment-10281 Pretty much the same as we've put in at my current client and we started it about 5 years ago so I can tell you it works and that yes, some of the data is dimensional "stars", but quite a bit doesn't conform to that approach, hence this multi layered approach. Do you not consider the "history" tables in the Foundation layer (we call ours Business Data Model - BDM) to be SCD2s? Pretty much the same as we’ve put in at my current client and we started it about 5 years ago so I can tell you it works and that yes, some of the data is dimensional “stars”, but quite a bit doesn’t conform to that approach, hence this multi layered approach.

Do you not consider the “history” tables in the Foundation layer (we call ours Business Data Model – BDM) to be SCD2s?

]]> By: Kaustubh http://www.rittmanmead.com/2009/07/16/drilling-down-in-the-oracle-next-generation-reference-dw-architecture/comment-page-1/#comment-10276 Kaustubh Thu, 16 Jul 2009 20:02:44 +0000 http://www.rittmanmead.com/2009/07/16/drilling-down-in-the-oracle-next-generation-reference-dw-architecture/#comment-10276 Thanks Mark , This was indeed really insightful. I hope you would write a reference on this as most of the time it is difficult for us to convince the users to convert to dimensional modeling for fear of loosing data and yet we are always unable to derive the full functionality of the BI tools on databases which are not dimensionally aware. Thanks Mark ,

This was indeed really insightful. I hope you would write a reference on this as most of the time it is difficult for us to convince the users to convert to dimensional modeling for fear of loosing data and yet we are always unable to derive the full functionality of the BI tools on databases which are not dimensionally aware.

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