Exadata Hybrid Columnar Compression

Saurabh K. Gupta's Oracle Blog

The basic idea behind the Exadata Hybrid Columnar Compression (hereby referred as EHCC) is to reprise the benefits of column based storage while sustaining to the fundamental row based storage principle of Oracle database. Oftentimes  the databases following column based storage claim that comparatively they needs less IO to retrieve a row than a row based storage. In a row based store, a row search requires entire table to be scanned which needs multiple IO’s. Hybrid columnar compression uses column based storage philosophy in compressing the column values while retaining the row based stores in a logical unit known as compression Unit. It helps in space storage by compression and yield performance benefits by reducing the IO’s. EHCC is best suited for the databases with less updates and low concurrency. Also it applies only to table and partition segments – not to Index and LOB segments.

How EHCC works? What…

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7 thoughts on “Exadata Hybrid Columnar Compression

  1. Unless the original poster has given you express, written permission to copy this article … haven’t you just committed plagiarism by copying part of his article?


      1. OK, then why not post just a link to his article? Are you helping him promote his web site? I don’t understand the purpose of what you did. Personally, I’d be upset if you copied one iota of my blog … as you should be if I copied any of your original work. Perhaps I just don’t understand … I apologize if it sounds like I was accusing you of plagiarism. BOL Jim


      2. When you reblog an article at the beginning of the article it gives you a link to the original article and it’s author. Even to read the full article you have to click on the Author’s original post. I’m not promoting the OP, it is just sharing of knowledge and doing that by fully acknowledging the work of the OP


      1. That I will do, sir. Again, I apologize if I have upset you; we here in the USA consistently see people stealing our work. One of my co-authors just had her whole book republished by someone else as a PDF, thus depriving her of any profit from over a year’s worth of personal endeavor.


      2. Please go ahead and reblog my articles if you please. I do understand the sensitivity of the plagiarism issue, but re blogging gives full acknowledgement of the original authors work.


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