Re: OT Bull-fight avoidance
Date: 29 May 2006 09:52:24 -0700
Message-ID: <1148921543.941589.171440_at_38g2000cwa.googlegroups.com>
Bob Badour wrote:
> Alfredo Novoa wrote:
> > Keith wrote:
> >
> >>The performance advantages of size constraints is
> >>fundamental.
> >
> > Only with lazy implementations.
>
> Alfredo, the performance advantages of size constraints are fundamental
> regardless--as are the performance disadvantages.
But at least some DBMSs have separate varchar types for 2^8 chars, 2^16, 2^24, and 2^32. I don't see much of a win in doing so. The one advantage I can imagine for this would be being able to use smaller pointers/offsets, which would then use less storage. But I don't see where a dbms would need to be storing pointers/offsets into a varchar, so wtf? And if we are talking about the implementation of library code for functions on varchars, I'd expect them all to use 32 bit pointers for traversing the attribute value, regardless of the max size of the type.
Marshall Received on Mon May 29 2006 - 18:52:24 CEST