Counter argument is that normalisation proceeds on facts, and not on entity. Which is where you argue denormalisation probably.
And what does that show Dummy?Isn't that obvious?
btw, An IQ test is only a measure of how well a person is at taking an IQ test, it cannotCorrect.
truly measure intelligence
Brilliant thoughts 3360 - enlightening my mind :PSelecting NULL resulting with one empty rowThe query returns null for each row in the table.
Dual has one row.
You got one null back.
If you want no nulls, query an empty table if it
confuses you less.
I'm afraid I don't know what those mean. I wasI don't think it's so much matter of normalisation but of orthogonality as I mention already. You end up ultimately with two ways to project the set of customers, either project id from customer, or project customer_id from union all of all reason not to have phone number tables, assuming all reasons are have mutual exclusion and that there is no customer such that they have no phone, had one but lost it, dont want a new one and wouldn't tell the number even if they had.
thinking that implementing n possible reasons
for something by defining n identical child
tables seems like a denormalisation to me