How long do you spend on your database?

dougal85

I was wondering how long you all spend designing and implementing your database?

I have done quite allot of work with them at university/work and personal investigation and I believe more and more from what I've seen, generally developers do not put enough timein put into database design. (when it comes to PHP+mysql dev - Ive not much experiences in other areas)

After all, Have you tried changing the structure of your database halfway through a project? Many of you will know how annoying that is or how annoying it is to work with a database that isn't well designed. My first experience of this was a few years ago when i was helping my friend with a PHP project he had for uni, he had been given a database to use and was to design a website to work as a front end to it. Anyway, it turned out to be one table containing about 25 fields... it wasn't even in First normal form!

What version of mySQL are people using? Does mySQL 4 still have the biggest coverage? I imagine it does. I find mySQL 5 so much better, it fills in some of the massive gaps mySQL had as a serious DBMS.

Anyway, I might cut this rant a little short. and see if anybody is interested 😛

In case you wondered, I just got work for a possible client and they suggested I used a database they had already to save time! omg... you should have seen it!

sneakyimp

It depends on the scope of the project. If I just need a user table for logins, I might spend 20 minutes.

I'm working on another project (an event listing) that has about 15 tables and I've been working for weeks doing load testing and stuff. I can't get the queries to run quickly enough! More on that here:

http://phpbuilder.com/board/showthread.php?t=10331619

I worked on another project that has maybe 120 tables and that took me over a year to get working fully...but most work was on the php end. On the other hand, the data comes from government sources that are a bit different each year so every 6 months there is an update which might require data changes.

A lot of it depends on client demands and the nature of the data.

Piranha

This far I have only designed small databases with 10-15 tables, and I have designed it from scratch. So I have had it quite easy to design it correct, and have not put that much time into the database itself. Everything I have done have had 4 NF to start with, and then I have the ability to add indexes to speed up the queries.

A few times I have added columns that break the normal forms, in cases that I need to speed up the database. But when I do that I make sure that the update of that value is done by triggers and triggers alone.

I have never had problems with the databases that I have designed. But I have had problems and have had to redo a lot in the PHP coding since I haven't desinged that good enough. My suggestion is that you make sure to design both the database and the PHP code on paper before you start programming. And if you should develop something from the start try to convince the customer that it will be more expensive for you to understand and use the database they have than it would be to design a new database.