Re: Oracle database configuration options

From: Thomas J. Kyte <tkyte_at_us.oracle.com>
Date: 1996/10/28
Message-ID: <3274d6bd.2327897_at_dcsun4>#1/1


On Mon, 28 Oct 1996 12:02:30 +0000, Jim Smith <jim_at_jimsmith.demon.co.uk> wrote:

>In article <Lli5bBAR45cyEwCP_at_pbrewer.demon.co.uk>, Paul Brewer
><paulb_at_pbrewer.demon.co.uk> writes
>>So we thought 'OK, let's just use VARCHAR2 all the time', but were
>>advised that this wasn't a good idea, as there would be a significant
>>performance impact when using VARCHAR2 columns in indexes, so we didn't
>>bother.
>>We're not yet too far down the road to change our approach, and would
>>welcome any comments or suggestions on this.
>
>I don't know of any formal trials, but the general view seems to be that
>there is no significant performance hit when using VARCHAR2
>--
>Jim Smith

there are none, a CHAR field is really a VARCHAR2 with blanks to pad it out to the max size. therefore a CHAR takes up the same amount of space (leading size indicator followed by data, the size is constant for the entire column, blanks pad out).

A number field is really like a varchar2(44). Numbers are stored in a varying length character-like field as well.

The only fixed sized field is a date (7bytes).

Thomas Kyte
Oracle Government
tkyte_at_us.oracle.com                          

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statements and opinions are mine and do not necessarily reflect the opinions of Oracle Corporation Received on Mon Oct 28 1996 - 00:00:00 CET

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