Oracle FAQ | Your Portal to the Oracle Knowledge Grid |
![]() |
![]() |
Home -> Community -> Mailing Lists -> Oracle-L -> RE: char vs. varchar2
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 -------------------------------------------------------------- http://www.oriole.com, designed by Oracle DBAs for Oracle DBAs -------------------------------------------------------------- -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Stephane Faroult INET: sfaroult_at_oriole.com Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists -------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Terrian, Tom INET: tterrian_at_daas.dla.mil Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists -------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).Received on Wed Aug 29 2001 - 14:38:14 CDT
![]() |
![]() |