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>Normalisation comes with costs; mainly performance. Most of use only normalize to 3 BCNF and not to the 5th normal form. It makes a lot of sense to first normalize your database and then identify the performance problem spots. Then just denormalize the database to fit your needs.



Hello Walter

I posted this earlier in the thread to add a bit of fun.


No you can never over normalize.

When reviewing one of my apps I noticed that the letter A had been used in my tables time and time again.

Looking further I noticed that all the other letters of the alphabet were also represented in this wasteful way,

To solve this problem I created a table with 26 records in it each representing the letters of the alphabet and had each letter looked up as it was used.

I then realised that these letters could be upper or lower case so altered this to 52 records.

I then hit upon the problem of punctuation characters....very wasteful and they can be used several thousand times in a big table.

To cut a long story short I have now managed to to fully normalize my application.

We have now had to upgrade to a Cray super computer to get the performance that we need from the app but I feel that is a small price to pay for doing things in a correct manner.

I.Pedant@Microsoft.com


(The above is not a true case study and should be reviewed with appropriate levity) <g>