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Home -> Community -> Usenet -> c.d.o.server -> Re: Pros and Cons of using Char and Varchar2
"Rene Nyffenegger" <rene.nyffenegger_at_gmx.ch> wrote in message
news:Xns907AE5A9BBC65gnuegischgnueg_at_130.133.1.4...
> >Cost: when varchar columns are updated they may be starting the feared
> >chained rows menace.
>
>
> What is the 'feared chained rows menace'?
>
> Rene
>
>
>
> --
> Rene Nyffenegger
> rene dot nyffenegger at adp-gmbh dot ch
>
>
The menace is you need 2 I/Os to fetch 1 row.
If your table has a substantial amount of chaining you will immediately
notice that.
In order to prevent that one of the guidelines is of course the block size
of your database should be bigger than your biggest rows.
If you have 3k rows and 2k blocksize, you are just asking for trouble.
Hth,
Sybrand Bakker, Oracle DBA Received on Thu Apr 05 2001 - 15:55:06 CDT