[Date Prev][Date Next]
Re: >= (greater or equal) and <= (lower or equal) operators in
Hallvard B Furuseth wrote:
Or one could design a new attribute that inherits from the old one
PLUS the ordering match; inheritance wwould let the new attribute be a
valid replacement for the old one without even hanging a line of code
(except where writes occur, of course) and add the new feature (an
mess everything up, of course).
Depends on how the attribute is used. If you then add the new attribute
instead of the old one, searches for both the old and the new attribute
would succeed. However, the old attribute will not be present in search
results, and old applications that expect to receive the old attribute
will not recognize the new one.
Yes, that's what's usually restraining me from exploiting inheritance
except in applications I personally develop and use. In this case
interoperability is going to be the real point. However, legacy
applications should disappear, and good legacy applications ususally
don't have attribute types hardcoded, but they can be configured, so
moving from the old to the new name should not be a problem.
SysNet - via Dossi,8 27100 Pavia Tel: +390382573859 Fax: +390382476497