I'm trying to convert a logical model to a physical model and I saw an example here http://www.1keydata.com/datawarehousing/data-modeling-levels.html which doesn't have null or not null. Next to the data types, does null or not null need to be in a physical model ?...Also I see a lot VARCHAR2(30) in the models, I know it depends on a situation of course but when would you have VARCHAR2(50) ? would you want it when you have a column something like description, location or street address ?
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What is your question? – Guido Leenders Jan 31 '14 at 18:41
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do you need null or not null next to data types in a physical model ? or is that optional ? – Ris Jan 31 '14 at 19:17
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1Depends on your notation method. Ultimately you must specify it in the ddl or the database engine chooses. – Guido Leenders Jan 31 '14 at 21:12