Re: [PHP] Re: Where to start!
[email protected] ("Tony Marston")
| Newsgroups | php.general |
|---|---|
| Message-ID | <[email protected]> |
"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] > > >