Re: Pros and Cons of using Char and Varchar2

Norberto Pontt O. wrote:
>
> 1.-CHAR TYPE
> Char type should be used for fixed length data.
> Such as codes
> A100
> B102
> B104
> Cost: It uses more blocks in the space in tablespace
> Benefits: No problems about Chained Rows
>
> 2.-VARCHAR2 TYPE
>
> Varchar2 stands for variable length data ( and for space saving)
> Such as
> Descriptions
> Notes
> Text explaining something about de record, etc.
>
> Cost: when varchar columns are updated they may be starting the feared
> chained rows menace.
> Benefits: it helps to save space in the tablespace assigned to the table
>
> Which one is better? Its a matter of design. Here are some clues:
> 1.-Use whatever one. It's up to you.
> Try using only one type so that you avoid problems about comparing varchar2
> against char (in the where part of the query) and not having the problem
> such as
> 'SMITH' <>'SMITH '
> 2.-Varchar2 produces the chained rows problem in the long trend. If the
> development project is just starting, leave the problem for dba people to
> solve it in the far away future.
> So if you want to save space use varchar2
> 3.-If your system might be migrated to some other sql bearing rdbms (other
> than oracle) then CHAR type might be better because it is an older standard.
>
> Well, that's all for today.
> Good Luck
>
> "Peter Shankey" <shankeyp_at_its.charlestoncounty.org> escribió en el mensaje
> news:20010405.15264600_at_wando.charlestoncounty.org...
> What are the issues why should I use one over the other.
>
> thanks
> Pete

If the data is fixed length, I'm not sure how CHAR uses more space, since both char and varchar2 are stored in the same way.

Connor

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Connor McDonald
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"Some days you're the pigeon, some days you're the statue"