Ann, > I think it would be wise to add a [NO] VALIDATION modifier to constraint > definitions, including NOT NULL and referential integrity definitions. > In the presence of a VALIDATION modifier, Firebird would begin enforcing > the constraint on commit (as now) and then start a pass to insure that > the data complies with the constraint. I'd also be tempted to add a > database configuration option that makes validation the default.
AFAIK, all constraints backed by indices (i.e. PK/UK/FK) were always validated upon creation. Well, upon commit, actually. Starting with v3, we also enforce NOT NULL constraints. The engine validates data when NOT NULL is added for an already populated column (also at the commit time). So CHECK constraints seem to be the only ones that are not validated upon creation. Surely doable some day. The good question is whether we really should be supporting the NO VALIDATION option. Personally, I don't like that, however I know that some other databases has such a feature. If somebody had a real need for that, please describe your use case(s). All that said, I see no need for a configuration option. Validation should be always the default behavior. Any RDBMS is first of all about consistency and only then about performance. Dmitry ------------------------------------------------------------------------------ Firebird-Devel mailing list, web interface at https://lists.sourceforge.net/lists/listinfo/firebird-devel
