[mafro]

This was my sentiment exactly. Any idea why he's so keen on sequential keys? They're mentioned as desirable several times in the article.

[matclayton]

The issue, particularly with innodb on MySQL is that the row data is stored with the primary key. By using GUID's and not sequential ids, you end up having to rearrange the entire dataset to insert the row data at the appropiate place, to keep the index in order, instead of appending it, killing your write performance.