The problem is that in SQL "primary" also implies "unique".

OK, I'll amend my statement to be "I can't imaging having a table
without a UNIQUE primary key" :)

And even that wouldn't be so bad if it didn't add a bunch of overhead.

I've not done the research, but given that you most likely have an index
on this non-unique key anyway, wouldn't the added overhead for unique be
trivial. You're already maintaining the index, all you're adding is a
statement that says "if there's already a row in this index with this
key, throw". You had to find the right point in the index to insert the
non-unique key, so the page is already in memory.


This thread ...


Follow On AppleNews
Return to Archive home page | Return to MIDRANGE.COM home page

This mailing list archive is Copyright 1997-2020 by and David Gibbs as a compilation work. Use of the archive is restricted to research of a business or technical nature. Any other uses are prohibited. Full details are available on our policy page. If you have questions about this, please contact [javascript protected email address].