Interesting paper. Clear and concise writing.
I don't take issue with point #4 below, though I
do question their terminology.
'Over Normalization' is hardly a good term for a
denormalization technique.
Jared
On Monday 07 May 2001 16:15, Eric D. Pierce wrote:
> from "The Data Administration Newsletter" (TDAN)
> http://www.tdan.com/i014ht04.htm
>
> DENORMALIZATION AND THE
> RULES OF RECONSTRUCTION
> Dick Root - Thistledown Consulting Services
>
...
>
> 4. Over Normalization (Vertical partitioning/segmentation) -
> This is the technique of splitting the original logical table into
> two or more physical tables. By assigning some of the columns to one
> physical table and some to another. Both tables end up with the same
> number of rows and have the same keys (see “Rule of Reconstruction”,
> below). Grossly this will increase performance since the individual
> tables are now smaller. In most DBMSs the negative affect of long
> column length is non-liner. The query time against a 1000 byte row
> length table can be more than twice the query time against a 500 byte
> row length table. So arbitrary vertical partitioning will cause much
> better performance against each of the separate partitions. If you
> are constantly joining the partitions, over normalization is self-
> defeating. Therefore, the trick is to cluster the columns together
> that are used together.
>
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