Re: maximum columns

"Sybrand Bakker" <postbus_at_sybrandb.demon.nl> wrote in message news:<tpqdvj8srvf310_at_news.demon.nl>...
> "kshathrya" <kshathrya_at_hotmail.com> wrote in message
> news:tpq4oiic3bgbe3_at_corp.supernews.com...
> > Hi,
> > I have a dataset which had 7000 columns and 38 rows. What is the best
> > way to load it into the database. Is there a different algorithm i can
> use.
> > WHat is the maximum columns supported by oracle?
> >
> > thanks
> > ks
> >
>
> 1000.
> Please try to look up questions like this in your manual, in this case the
> Oracle Server Reference Manual. As Oracle comes with a master index, that
> shouldn't be too difficult a task.
> Apart from that a table with 1000 columns would most likely be highly
> unnormalized.
>
> Regards,
>
> Sybrand Bakker, Senior Oracle DBA

The idea that data must be denormalized just because there are 1000 columns in a row is absurd. This may not be common in most traditional systems but when dealing with statistical process control and electronic control modules it is very possible to have a 1000 fields all fully dependent on the PK.

But Oracle stores rows with more than 254 (or 255) columns in row segments (peices) and there are extra IO's involved in fetching these segments to build the row so I am not sure you are not better off to store each row in a separate table. I think the answer depends on if any groups of the columns are needed for one screen or application and the others are not. I find it very difficult to work with long rows, but sometimes the data does in fact fit the rules.

• Mark D Powell --