LifeinAsia - 3:47 pm on Aug 27, 2010 (gmt 0)

I notice in most database abstraction classes for PHP, most select methods simply assume that you wish to select all fields from a row

For showing examples, it's less confusing to keep things simple. The more details you show, the more likely people will miss the important points.

In practice, it's generally better to just select the fields you need. Especially if you are returning a lot of rows.

Think of it this way, all the fields that you don't need have to be stored into memory. If your application server is on a different box from your database server, that unneeded data also has to be passed across the network.