Posted by Erland Sommarskog on 09/22/05 00:05

(mittal.pradeep@gmail.com) writes:
> 1. But the data collection and reporting is in horizontal format. If
> collected data is edited vertically, won't there be a extra steps of
> converting horizontally obtained data to vertical and then vertical to
> horizontal reports. In custom column model data always remains
> horizontal. Won;t performance not be a issue in taking care of two
> extra steps required in vertical model.

If you are to present ten of those custom values as columns in a report,
you get a 10-way self-join. Certainly bulky in code. Performance is
probably not top-notch, but I don't see that it would be absymal.

> 2. Won;t the concurrency be a issue, considering the fact that a
> logical single horizontal row is edited as say 10 rows. Two people
> might be changing same Primary key's different attributes at the same
> time.

Good point. This can be handled fairly easily, but it requires more
careful programming than the horizontal method.

Overall, there certainly is a tradeoff. If the set of custom fields are
faily stable, only change once per year or so, you might be prepared to
take the extra maintenance cost. But if users asks for new fields every
week, then the horizontal method could be a nightmare.


--
Erland Sommarskog, SQL Server MVP, esquel@sommarskog.se

Books Online for SQL Server SP3 at
http://www.microsoft.com/sql/techinfo/productdoc/2000/books.asp

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