Monday 3 December 2012

Top-Down vs. Bottom-Up In Data Warehousing


Data warehouse systems have gained popularity as companies from the most varied industries realize how useful these systems can be. A large number of these organizations, however, lack the experience and skills required to meet the challenges involved in data warehousing projects. In particular, a lack of a methodological approach prevents data warehousing projects from being carried out successfully. Generally, methodological approaches are created by closely studying similar experiences and minimizing the risks for failure by basing new approaches on a constructive analysis of the mistakes made previously.
This chapter considers a few methodological approaches mentioned in the literature that describe how best to manage data warehouse lifecycles. This chapter also defines our methodological approach to a data mart project.
Top-Down vs. Bottom-Up
When you consider methodological approaches, their top-down structures or bottom-up structures play a basic role in creating a data warehouse. Both structures deeply affect the datawarehouse lifecycle.
If you use a top-down approach, you will have to analyze global business needs, plan how to develop a data warehouse, design it, and implement it as a whole. This procedure is promising: it will achieve excellent results because it is based on a global picture of the goal to achieve, and in principle it ensures consistent, well integrated data warehouses. However, a long story of failure with top-down approaches teaches that:
  • high-cost estimates with long-term implementations discourage company managers from embarking on these kind of projects;
  • analyzing and bringing together all relevant sources is a very difficult task, also because it is not very likely that they are all available and stable at the same time;
  • it is extremely difficult to forecast the specific needs of every department involved in a project, which can result in the analysis process coming to a standstill;
  • since no prototype is going to be delivered in the short term, users cannot check for this project to be useful, so they lose trust and interest in it.
In a bottom-up approach, data warehouses are incrementally built and several data marts are iteratively created. Each data mart is based on a set of facts that are linked to a specific company department and that can be interesting for a user subgroup (for example, data marts for inventories, marketing, and so on). If this approach is coupled with quick prototyping, the time and cost needed for implementation can be reduced so remarkably that company managers will notice how useful the project being carried out is. In this way, that project will still be of great interest.
The bottom-up approach turns out to be more cautious than the top-down one and it is almost universally accepted. Naturally the bottom-up approach is not risk-free, because it gets a partial picture of the whole field of application. We need to pay attention to the first data mart to be used as prototype to get the best results: this should play a very strategic role in a company. In fact, its role is so crucial that this data mart should be a reference point for the whole data warehouse. In this way, the following data marts can be easily added to the original one. Moreover, it is highly advisable that the selected data mart exploit consistent data already made available.

70 comments:

  1. Asoka Packers and Movers Hyderabad is the most consistently ranked packers and Movers Company and has delivered over 56,000 homes all over India
    Packers and Movers Bangalore
    Packers and Movers Pune
    Packers and Movers Delhi
    Packers and Movers Gurgaon

    ReplyDelete
  2. It was really a nice article and I was really impressed by reading this article We are also giving all software Course Online Training. The Data Warehousing Courses Online Training is one of the leading Online Training institute in the world.

    ReplyDelete
  3. Nice comparison between two strategies.

    ReplyDelete
  4. Thanks for sharing this informative information. For more you may refer http://www.s4techno.com/hadoop-training-in-pune/

    ReplyDelete
  5. I have read your information its very useful topic for me. Thanks for providing information.
    Big data Hadoop Training

    ReplyDelete
  6. Analogica data is a one of the Best Big Data Services Provider Company in India, provide acumens on operations, products and customers. We also support predictive analysis,Big Data Services, master data management, and real time dashboards.

    ReplyDelete
  7. I just stumbled upon your blog and wanted to say that I have really enjoyed reading your blog posts. Any way I’ll be subscribing to your feed and I hope you post again soon.

    Dataware Housing Training in Chennai

    ReplyDelete
  8. Very nice post and i also used this services, thanks for sharing about Warehousing services and Household Shifting services.

    ReplyDelete
  9. Thanks for sharing such a valuable information.This post is very useful for me.Analytics Services Provider in Gurgaon

    ReplyDelete
  10. nice post data warehouse training is best it easy to understand
    it have the platform to get the technical knowledge.online training course more useful for us.thanks for giving this kind of to us you are the different level .
    dataware housing training in chennai

    ReplyDelete
  11. Nice post! I thank you for sharing this nice blog with us. Likewise, I would like to say something that Happy Heap Marketing is also one of the
    Best Digital Marketing Training in Gurgaon

    ReplyDelete
  12. Thanks for sharing such a valuable information.This post is very useful for me.
    Best Digital Marketing Training in Gurgaon
    .Thanks lots for sharing them with us.

    ReplyDelete

  13. Privileged to read this blog on Informatica.Commendable efforts to put on research the Informatica.Please enlighten us with regular updates on Informatica.Friends if you're keen to learn more about AI you can watch this amazing tutorial on the same.
    https://www.youtube.com/watch?v=56vMQ1lG-vc

    ReplyDelete
  14. Hey! nice blog really your information is useful to us thanks Informatica Online Training

    ReplyDelete
  15. Thanks for the explanation. It’s really helpful. Please keep sharing
    Big Data Training in Delhi

    ReplyDelete
  16. Very nice blog.It is very helpful for the beginners.
    Big Data Training in Delhi

    ReplyDelete
  17. I have read this post. collection of post is a nice one Informatica Online Course Hyderabad

    ReplyDelete
  18. I Feel extremely cheerful to have seen your website page and anticipate such a significant number of all the more engaging circumstances perusing here. Much appreciated yet again for every one of the points of interest.
    Hadoop Online Training in Hyderabad

    ReplyDelete
  19. This comment has been removed by the author.

    ReplyDelete

  20. Nice blog..! I really loved reading through this article. Thanks for sharing such a amazing post with us and keep blogging...
    Informatica online training in Hyderabad

    ReplyDelete
  21. It is amazing and wonderful to visit your site.Thanks for sharing this information,this is useful to me...
    Click here:
    python training in annanagar
    Click here:
    python training in velachery

    ReplyDelete
  22. Wonderful article, very useful and well explanation. Your post is extremely incredible. I will refer this to my candidates...
    Blueprism training in velachery

    Blueprism training in marathahalli


    AWS Training in chennai

    ReplyDelete
  23. This is most informative and also this post most user friendly and super navigation to all posts... Thank you so much for giving this information to me.. 
    Devops Training in Chennai
    Devops Training in Bangalore

    ReplyDelete
  24. Nice and good article. It is very useful for me to learn and understand easily. Thanks for sharing your valuable information and time. Please keep updatingmicrostrategy online training

    ReplyDelete
  25. That was a great message in my carrier, and It's wonderful commands like mind relaxes with understand words of knowledge by information's.
    Data Science training in Chennai | Data science training in bangalore
    Data science training in pune | Data science online training
    Data Science Interview questions and answers

    ReplyDelete
  26. Thanks you for sharing this unique useful information content with us. Really awesome work. keep on blogging
    java training in chennai | java training in USA

    java training in indira nagar

    ReplyDelete
  27. Thank you for this post. Thats all I are able to say. You most absolutely have built this blog website into something speciel. You clearly know what you are working on, youve insured so many corners.thanks

    angularjs online Training

    angularjs Training in marathahalli

    angularjs interview questions and answers

    angularjs Training in bangalore

    angularjs Training in bangalore

    angularjs online Training

    ReplyDelete
  28. Hello there! This is my first comment here, so I just wanted to give a quick shout out and say I genuinely enjoy reading your articles. Can you recommend any other blogs/websites/forums that deal with the same subjects? Thanks.
    python training in rajajinagar
    Python training in bangalore
    Python Online training in usa

    ReplyDelete
  29. Do you have a spam issue on this website; I also am a blogger, and I wanted to know your situation; many of us have developed some nice methods, and we are looking to trade methods with others, why not shoot me an e-mail if interested.
    python training Course in chennai
    python training in Bangalore
    Python training institute in bangalore

    ReplyDelete
  30. Have you been thinking about the power sources and the tiles whom use blocks I wanted to thank you for this great read!! I definitely enjoyed every little bit of it and I have you bookmarked to check out the new stuff you post
    Microsoft Azure online training
    Selenium online training
    Java online training
    Python online training
    uipath online training

    ReplyDelete

  31. Thank you for sharing such great information very useful to us.
    Data Warehousing Training in Noida

    ReplyDelete
  32. This comment has been removed by the author.

    ReplyDelete
  33. Its as if you had a great grasp on the subject matter, but you forgot to include your readers. Perhaps you should think about this from more than one angle.
    date analytics certification training courses
    data science courses training

    ReplyDelete
  34. I see some amazingly important and kept up to length of your strength searching for in your on the site



    Data Science Course malaysia

    ReplyDelete
  35. http://completedwh.blogspot.com/2012/12/top-down-vs-bottom-up-in-data.html

    ReplyDelete
  36. This post is very simple to read and appreciate without leaving any details out. Great work!
    big data course

    ReplyDelete
  37. After reading your article I was amazed. I know that you explain it very well. And I hope that other readers will also experience how I feel after reading your article.

    Simple Linear Regression

    Correlation vs Covariance

    ReplyDelete
  38. I have to search sites with relevant information on given topic and provide them to teacher our opinion and the article.
    learn360digitmg data science course

    ReplyDelete
  39. I want to say thanks to you. I have bookmark your site for future updates.
    360digitmg business analytics training

    ReplyDelete
  40. Thank you for taking the time to provide us with your valuable information. We strive to provide our candidates with excellent care and we take your comments to heart.As always, we appreciate your confidence and trust in us
    Artificial Intelligence Certification Course
    Java Certification Course
    AWS Certification Course
    Machine Learning Certification Course
    Data Science Certification Course
    DevOps Certification Course

    ReplyDelete
  41. Personally I think overjoyed I discovered the blogs.
    360digitmg data science institutes

    ReplyDelete
  42. Actually I read it yesterday but I had some thoughts about it and today I wanted to read it again because it is very well written.
    360digitmg data science course

    ReplyDelete
  43. It is an informative blog. I would like to know more information. Anyway thanks a lot for sharing this post. Those guidelines additionally worked to become a good way to recognize that other people online have the identical fervour like mine to grasp great deal more around this condition.
    Data Science Training In Chennai

    Data Science Online Training In Chennai

    Data Science Training In Bangalore

    Data Science Training In Hyderabad

    Data Science Training In Coimbatore

    Data Science Training

    Data Science Online Training

    ReplyDelete
  44. Such a very useful article. Very interesting to read this article.I would like to thank you for the efforts you had made for writing this awesome article.

    Simple Linear Regression

    Correlation vs Covariance

    ReplyDelete
  45. Wonderful article, very useful and well explanation. Your post is extremely incredible. I will refer this to my candidates...data science courses

    ReplyDelete
  46. Such a very useful article. Very interesting to read this article.I would like to thank you for the efforts you had made for writing this awesome article. data scientist courses

    ReplyDelete
  47. Thanks for sharing this wonderful information. I too learn something new from your post..
    Informatica Training in Chennai
    Informatica Training in Bangalore
    Informatica Course in Chennai

    ReplyDelete
  48. I really thank you for the valuable info on this great subject and look forward to more great posts
    data scientist training in hyderabad

    ReplyDelete
  49. I have to agree with everything in this post. Thanks for useful sharing information.
    Python Training in Hyderabad
    Python Course in Hyderabad

    ReplyDelete
  50. I am interested in reading about more of the similar topics and would like to have further information on the same subject. Hope to see the next blog soon. Thanks.
    DevOps Training in Hyderabad
    DevOps Course in Hyderabad

    ReplyDelete
  51. I simply wanted to thank you so much again. I am not sure the things
    that I might have gone through without the type of hints revealed by
    you regarding that situation.
    unix training in chennai
    Software training institute in chennai

    ReplyDelete
  52. This comment has been removed by the author.

    ReplyDelete
  53. This comment has been removed by the author.

    ReplyDelete