Oracle Scratchpad

May 19, 2011


Filed under: CBO,Indexing,Oracle — Jonathan Lewis @ 8:41 am BST May 19,2011

Being a very reserved British type of character I’m not really one to make a big fuss about advertising myself, which is why it’s taken me five years to realise that I ought to make it easy for people to find the free download of Chapter 5 (Clustering Factor) of Cost Based Oracle Fundamentals.

Apress changes the relevant URL from time to time, and I’ve just discovered that they’ve now bundled the pdf file of the chapter into this  zip file.

The thing that prompted me to post this special note was that some time ago Mohamed Houri translated the chapter into French as a gesture of appreciation for the fact that I had written the book and Apress has given me permission to post the translation, which is this pdf file.


  1. Jonathan,

    Although most of regular blog readers have already bought your “Cost Based Optimizer Fundamentals” (at least I hope so), it is nice to find your downloadable chapter here.

    How did you enjoy Prague? I really regret I couldn’t attend your course this time (but I have sent some colleagues :) )

    Comment by Pavol Babel — May 19, 2011 @ 7:10 pm BST May 19,2011 | Reply

    • Pavol,

      Prague is a lovely city – I always enjoy visiting it.
      I hope your colleagues enjoyed the seminar and found is useful.

      Comment by Jonathan Lewis — May 22, 2011 @ 11:55 am BST May 22,2011 | Reply

      • Jonathan,

        collegues were stasfied, they really enjoyed your seminar. I hope you will visit Prague or Bratislava in few years again

        Comment by Pavol Babel — May 25, 2011 @ 10:23 am BST May 25,2011 | Reply

        • Pavol,

          Thanks for the comment.
          You can be pretty sure that I’ll be back some time in the next couple of years.

          Comment by Jonathan Lewis — June 2, 2011 @ 8:10 pm BST Jun 2,2011

  2. Last year I translated your article: Designing Efficient SQL: A Visual Approach
    into Chinese and posted it on a Chinese Forum:

    Sorry I forgot to ask for your permission and I hope it’s not too late. Thank you!

    Comment by James Su — May 19, 2011 @ 8:37 pm BST May 19,2011 | Reply

    • James,

      You should have emailed the people at SimpleTalk who published the article originally. However I note that you did include a link to the original article in your translation, and the agreement I had with them was that I wouldn’t republish anywhere else for 6 months (and your article translation appeared 8 months later); so it falls to me to say that I don’t mind – you clearly weren’t trying to take credit for the article, and I’m quite happy for people to translate the material I write, although it’s better to ask permission first.

      I’ve linked to the forum article from my catalogue of Chinese Translations in the column at the top right.

      Comment by Jonathan Lewis — May 22, 2011 @ 12:10 pm BST May 22,2011 | Reply

  3. I’m grateful you and Apress permit a free download of the Clustering Factor chapter of your book. It is a valuable resource on a topic that is not very well documented in the Oracle docs. Cost Based Oracle Fundamentals should be on the bookshelf of every Oracle professional.

    Comment by Jimmy — May 21, 2011 @ 3:49 pm BST May 21,2011 | Reply

    • Jimmy,

      Thanks for the comment – I quite agree.

      Personally I think everyone should have three copies: one at home, one at work, and one to lend to their colleagues.

      Seriously, though, I think that Apress has picked the most important chapter in the book as the free download (others may disagree.)

      Comment by Jonathan Lewis — May 22, 2011 @ 12:22 pm BST May 22,2011 | Reply

  4. The pdf doesn’t download properly. I tried to download several times. Can you check?

    Comment by Nitin — December 14, 2011 @ 2:50 am BST Dec 14,2011 | Reply

    • Nitin,

      I’ve just tried to download the pdf file and the zip file, and they both download with no problems. What happens when you try ?
      The pdf is in the zip, by the way, so if you can download the zip you won’t need the pdf.

      Comment by Jonathan Lewis — December 14, 2011 @ 12:28 pm BST Dec 14,2011 | Reply

  5. […] This is what I call buffer re-visits. (Now scroll back up and see what is that index’es clustering factor […]

    Pingback by About index range scans, disk re-reads and how your new car can go 600 miles per hour! | Tanel Poder's blog: Responsible data management — September 17, 2014 @ 9:56 am BST Sep 17,2014 | Reply

  6. […] Clustering Factor (Jonathan Lewis book) […]

    Pingback by Publications | Mohamed Houri’s Oracle Notes — October 24, 2014 @ 11:02 am BST Oct 24,2014 | Reply

  7. […] having to re-visit the same datablocks multiple times (up to one visit per row, depending on the clustering factor of the index used). This would cause another logical IO and use more CPU cycles for each buffer […]

    Pingback by RAM is the new disk – and how to measure its performance – Part 3 – CPU Instructions & Cycles | Tanel Poder's Performance & Troubleshooting blog — November 30, 2015 @ 6:46 am BST Nov 30,2015 | Reply

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