RE: Otional FK in Informix?

> >If I recall correctly Date also says denormalization for any reason > >(including DSS star schema) is an abortion which shouldn't > ever be used. > > I'm with him there too. I've never denormalized in 20-odd > years of building > systems. > I've used denormalization occasionally (although I didn't inhale) - especially under Oracle. Where the cost of joining two tables is exceptionally high, and the amount of data to be added/updated in both tables is not that bad. Imagine if you had to pull several million rows from someplace, and the database wanted to use a nested loop to join the two tables - each with 100's of millions of rows. You might be there for a while (think days). However, I much prefer normalized data, with (is this a plug?) the WONDERFUL hash join, it's not an issue. I once ran into a data model under SE that was horribly de-normalized. To, in my mind, a crippling extent. I converted the guys data into a normalized model and benchmarked the two - the normalized model could not beat the denormalized one for his application by a factor of 2 to 1. cheers j.