"Jason Pruim" <[EMAIL PROTECTED]> wrote in message 
news:[EMAIL PROTECTED]
>
> 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
> [EMAIL PROTECTED]
>
>
> 



-- 
PHP General Mailing List (http://www.php.net/)
To unsubscribe, visit: http://www.php.net/unsub.php

Reply via email to