On Tue, May 4, 2010 at 9:40 AM, Merlin Moncure <mmoncure@gmail.com> wrote:
> On Sat, May 1, 2010 at 4:14 PM, John R Pierce <pierce@hogranch.com> wrote:
>>
>> If your 'natural key' is a large text field, I'd have to assume there's some
>> point at which a surrogate index would be more efficient. Would this be
>> above a few dozen characters, or a few 100 characters? I wouldn't want a
>> PK based on a multi-K byte text field for a table that has many 10s or 100s
>> of 1000s of rows, for sure.
one more note about this. if you truly have a situation where a multi
kilobyte chunk of data is the key, you can always digest it and use
that. you lose the natural ordering -- but in these type of cases it
usually doesn't matter.
merlin