Julian,

I am not aware of any databases smart enough to decide to create references
for rows whose data is identical to an existing row.  If the duplicate data
is creating resource issues, there's a couple things that you can do to
eliminate the duplicate data.  Probably the easiest would be, in the case of
varchar data, to add a column for a row number.  If the data to be inserted
is identical to data in a row that's already in the database, an encoded
reference to the row number of the row with the original data could be
stored.  That way, you're just storing the reference to the original data.

Example:

RowNum     ProdNum     Revision     Description_varchar
455333        10                1
XXXYYYXXXYYYXXXYYYXXXYYYZZZYYYYXXXX
873245        10                2               <<-455333->>
934532        10                3               <<-455333->>

If you don't want to do the encoding thing, you could create a "link" table
to accomplish the same thing.

HTH,
James Potts


"Julian Wood" <[EMAIL PROTECTED]> wrote in message
[EMAIL PROTECTED]">news:[EMAIL PROTECTED]...
>
> Hi,
>
> Don't know if this is the best place to ask, but I thought I would give
> it a try.
>
> I was just wondering if anyone knows of any databases which deal with
> data duplication (at a low level). Say I have two (or ten) identical
> records, does anyone know of any databases which would only keep one
> copy of the data and use references for the other records? Does this
> work if 7 out of the 8 columns (for instance) are identical (ie the
> primary key is different but everything else is identical). Do such db's
> exist? Or do they all do this? Or am I just dreaming?
>
> J
> --
> Julian Wood
>
> Programmer/Analyst
> University of Calgary



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