"Jason Pruim" <japruim@raoset.com> wrote in message
news:36133942-D547-43E4-9521-8B8C1D80D206@raoset.com...
>
> On May 5, 2008, at 6:21 AM, Tony Marston wrote:
>
>>
>>
>>
>> Anyone who doesn't know how to reach 3NF shouldn't be designing
>> databases.
>
> Just out of curiosity... How many Records do you need to have in a
> database before you'll start seeing a performance boost from doing that?
> I have written a few database apps that work quite well with no formal
> training in PHP or Database design.. Don't want to start any wars here...
> I'm just curious :)

It is not the number of records which is the deciding factor - it is:
a) is the data want in the right place (for easy access)?
b) can it be upated easily?

For example, many years ago I had to take over maintenance of a database
which was designed b someone who was not technically competent. There were 2
paticular tables, "order_header" and "order_lines". The order had a status
value, as did each of the order lines. So where did this twit choose to
store the order status? - you've guessed it, on the order_line record. His
rationale was that when traversing the order_line recods it was easier to
have the order_status on that record instead of having to perform a separate
read of the order_header record. The flaw in this argument was that when you
wanted to change the status of an order you had to update every order_line
record. Problems arose later when a software bug (introduced by him, BTW)
left different values for order_status across different order_lines.

The rules of normalisation dictate that order_status goes on the
order_header record, and is not dupliacted across several order_line
records.

--
Tony Marston
http://www.tonymarston.net
http://www.radicore.org


> --
>
> Jason Pruim
> Raoset Inc.
> Technology Manager
> MQC Specialist
> 3251 132nd ave
> Holland, MI, 49424-9337
> www.raoset.com
> japruim@raoset.com
>
>
>