Re: Please check the model for errors
Posted by:
Rick James
Date: April 17, 2010 07:18PM
I prefer the iterative method.
1. sketch out ERD (you did that)
2. write CREATE TABLEs -- this might lead to some issues having to do with constraints that the database gives.
3. estimate sizes -- If this will be a 'huge' database, performance considerations need to be considered this early. Go back to #2.
4. Write the SELECTs. Oops, the ERD and/or Schema do not support some of the SELECTs; go back to step 1 or 2.
5. INSERT some data (even if it is facricated).
6. (If huge) Write a script to generate a huge amount of data. Check performance; iterate if needed.
Over-normalization can be somewhere between bad and terrible for performance on Huge tables.
Under-normalization can lead to clumsy code, mostly in the form of extra UPDATE statements when a value changes.
Normalization will lead to extra steps to look up ids, given strings. This is worth it in the long run.
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Re: Please check the model for errors
April 17, 2010 07:18PM
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