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RE: char vs. varchar2

From: Terrian, Tom <tterrian_at_daas.dla.mil>
Date: Wed, 29 Aug 2001 12:38:14 -0700
Message-ID: <F001.0037BF60.20010829125727@fatcity.com>

Thank you, I will check it out.

Tom Terrian
Oracle DBA
WPAFB - DAASC
tterrian_at_daas.dla.mil
937-656-3844

-----Original Message-----
Sent: Wednesday, August 29, 2001 4:06 PM To: Multiple recipients of list ORACLE-L

"Terrian, Tom" wrote:
>
> I think that this subject comes up now and then, but I don't remember the
> conclusions........
>
> We are creating a Data Warehouse and the subject of char vs varchar2 data
types
> came up. I searched google and found a little bit on the subject (mainly
there
> is no space savings between char(1) and varchar2(1)).
>
> Has anybody studied this? For example: If I know that all my data is 10
> characters wide, should I not create the field as char(10)? Any reason to
make
> it a varchar2(10)? Would sql scripts (select and dml) be faster with one type
> or the other? Any space savings with one type or the other (still given 10
> characters of fixed data)?
>
> Thanks,
> Tom
>
> Tom Terrian
> Oracle DBA
> WPAFB - DAASC
> tterrian_at_daas.dla.mil
> 937-656-3844

Tom,

  There is a somehow astonishingly little known - in spite of its having been around for at least the 15 last years - SQL function named VSIZE() which answers any question you may have about actual storage usage. For the really inquisitive, you have DUMP() as well.

-- 
Regards,

Stephane Faroult
Oriole Corporation
Voice:  +44  (0) 7050-696-269 
Fax:    +44  (0) 7050-696-449 
Performance Tools & Free Scripts
--------------------------------------------------------------
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Author: Stephane Faroult
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Author: Terrian, Tom
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Received on Wed Aug 29 2001 - 14:38:14 CDT

Original text of this message

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