Re: How many columns can one table have

there are probably other limiting factors... such as performance. remember that
to access a value of a column in a given row, oracle needs to check the lengths
of all of the columns prior to it in order to determine its location in the row.

in order to support 1000 columns, oracle only needed to find another 2 bits for the length field.

"Billy Verreynne" <vslabs_at_onwe.co.za> wrote in message news:39095578.1307964370_at_news.saix.net...
> "Sybrand Bakker" <postbus_at_sybrandb.demon.nl> wrote:
>
> >the maximum number is 254 in Oracle 6 and 7, and 1000 in
 Oracle 8,
> >regardless of 32 or 64 bit
>
> This does not make a lot of sense to me Sybrand. One of those
 strange
> Oracle phenomena... ;-)
>
> 255/256 does. This the max value that can be stored in a
 single byte
> (unsigned 8 bit : 0..255) - the assumption being of course
 that the
> size of the variable used to represent the column number is
 the
> limiting factor.
>
> A 1000 columns.. If Oracle switched from a single byte value
 to a two
> byte integer value (an unsigned 16 bit word), then the max
 value is
> 65,535.
>
> Any thought to why Oracle has selecting to impose artificial
 limits
> instead?
>
> regards,
> Billy
>
>
>
Received on Fri Apr 28 2000 - 00:00:00 CDT