Table with 255 columns or more…

I wrote a BLOG on the Intra Row Chaining and the issues around this for a table that has more than 255 columns. Jonathan Lewis has written a very fantastic blog on this subject with some more explanation and a real life example. Worth Reading.

Jonathan’s Link

During my recent AIOUG OTN Yathra Tech Day in Chandigarh, I also demonstrated the CPU Cycles required for a Column Skip. This means, apart from the extra I/O required to read a column of a larger table, the CPU consumption will also be higher. Since this topic has come up and Jonathan nicely touching this subject, I would post the CPU calculation Blog in a day or so.

While the issue due to Intra Block Chaining is already published, the next blog will focus more on the CPU Cycles for column skipping for a small table (say with 14 columns) and then, this can be further co-related for a table with more columns. This will help DBA’s predict or evaluate the impact of the change (adding a new column) before being implemented on production. Also, a reason to have frequently queried on the top (Storage Space v/s CPU Consumption).

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About Vivek Sharma
I am an Oracle Professional from Mumbai (India). I blog on the issues that I feel is Interesting for my readers. Some of these are my real life examples, which I hope, you would find interesting. Comments are always a welcome. The Technical Observations & Views here are my own and not necessarily those of Oracle or its affiliates. These are purely based on my understandings, learnings and resolutions of various customer issues.

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