Re: Number of Columns in a Table & SQL Performance ?

From: Martin Berger <>
Date: Mon, 9 Mar 2009 22:26:29 +0100
Message-Id: <>


if this leads to chained rows (which is not unlikely at 400 columns and small blocksizes) you will see an affect in performance for sure. Otherwise there are pros and cons, depending on your actual data and access.

I personally have not seen any useful table with 400 columns yet, but your case might be reasonable.

There is also a little cost and performance penalty accessing the later columns, as oracle has to traverse all columns to reach the latest requested, so choose the column order wise.


Am 09.03.2009 um 14:19 schrieb VIVEK_SHARMA:

> Folks
> Does the number of columns in a table affect the performance of
> If so, why?
> NOTE - Merge of 2 existing tables each has 200 columns approx into a
> single Table is being planned..
> Thanks in Advance
> Vivek


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Received on Mon Mar 09 2009 - 16:26:29 CDT

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