Kyle wrote:
> On Fri, 10 Oct 2008 00:35:15 -0700, Darren New <dne### [at] sanrrcom> wrote:
> 
>> Likely correct. This doesn't really help too much if you don't have 
>> check-constraints tho. 
> 
> You would still want a check constraint, driven by the account type.

Sure. MySql doesn't support them, tho.  Definitely gonna use postgresql 
for the next project I get to start from scratch. :-)

> Does MySql use much space for null values?  Either way, that's really a non-issue,
compared to the benefit of data integrity.

I think I said that. :-)

>> and you can add a new type of account without having to frob 
>> the big table. 
> 
> It boils down to "alter big-table" vs. "create new-table".  With "create new-table",
you'd additionally have to set up foreign key constraints back to the big table's
primary key.  You'd have to
> modify the check constraint in either case.

Sure. With "create new-table", you don't have to worry about whether you 
broke any part of the program that doesn't deal with the new types of 
accounts, at least.  But it's really half of one, a dozen of the other, 
I'll agree. :-)

-- 
Darren New / San Diego, CA, USA (PST)

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