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Re: char(1) VS varchar2(1)

From: Tim Gorman <>
Date: Mon, 03 Nov 2003 18:54:25 -0800
Message-ID: <>

Yes! RMOUG Training Days is going to be an incredible event this year! A 2-day conference in Colorado during ski season with a lineup of speakers that rivals the major international conferences, including keynotes by Bill Inmon and Sue Cook! We're going to have a blast; I'm looking forward to meeting you!

on 11/3/03 2:59 AM, Tanel Poder at wrote:

> Hi!

>> Trailing columns with NULL values do not occupy any space, not even a

> length
>> byte.

> Yep, I missed this one. Also, when few trailing null columns aren't stored
> in a row, this particular rows column count is smaller as well, so the
> column count in physical table storage can vary...
>> Non-trailing columns with NULL values have a constant value of 0xFF (255)

> in
>> the length byte consuming just the one byte.

> Yep, and this means that even fixed-length CHAR datatypes don't consume any
> space except length byte if they contain nulls. I once saw a recommendation
> to store your data in char columns if you don't want to have to worry about
> row size changes and PCTFREE setting... which is mostly a stupid suggestion
> anyway and doesn't work in case of nulls either.
> Tanel.
> P.S. Tim, I assume that we'll meet at RMOUG training days this Feb?
Please see the official ORACLE-L FAQ:
Author: Tim Gorman

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Received on Mon Nov 03 2003 - 20:54:25 CST

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