On Apr 2, 2006, at 6:13 PM, Tom Lane wrote:
"Jonah H. Harris" <[EMAIL PROTECTED]> writes:
On 4/2/06, Tom Lane <[EMAIL PROTECTED]> wrote:
If you're expecting that you'll be able to write BYTEA(n) and avoid
storing a length word, you'll find that it's not a trivial matter.
It may not be trivial, but it's certainly not impossible.
A word to the wise is sufficient: function result types don't have
known typmods, and for the most part expression results don't either.
Changing that is not "impossible", but the level of pain vastly
exceeds
what this feature would be worth. And that's not even the only
problem.
If you're desperate to have something like this, you could create one
or more fixed-size datatypes (ie, with various positive typlen
values).
But I don't see a practical way to use a typmod in determining the
physical width.
I'm not sure how other databases handle this, but I suspect it would
be OK performance-wise to tack on a length byte for these types when
dealing with functions and anything else that isn't directly tied to
a table where you can easily get length info from the catalog.
Actually, how is this handled with varchar(x)?
--
Jim C. Nasby, Sr. Engineering Consultant [EMAIL PROTECTED]
Pervasive Software http://pervasive.com work: 512-231-6117
vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461
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