The only problem is detecting that the data is identical in the first 
place. If I have to do a select with 7 AND statements to see if I have 
identical data, I'm going to take a huge performance hit. I was hoping 
this had been done at a very low level, but it doesn't look like it. 
Maybe it's just as unrealistic at  a low level, but I could swear I had 
heard of this feature before.

Oh well.


PS. I didn't mention this before, but a link table (ie a relational 
structure) is not possible in my situation.

On Wednesday, August 29, 2001, at 01:47 PM, james wrote:

> 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
> 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
>> 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

University of Calgary
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