On Thu, Oct 28, 2010 at 8:35 PM, <[email protected]> wrote: > In database queries, it is often useful to treat an empty value specially, > and be able to search explicitly for records that have (for instance) no > field X, or no value for field X. I can't regurgitate offhand all the > precise situations that I've used this and claim that they would apply to a > search engine, but it is conceivable that it could be helpful to somebody. > Would your proposed change preclude current or future support for such null > queries?
in a database, not having a value for field X is 'null'. 1. null is different than empty term. 2. comparing this concept with an inverted index vs a database record really isn't a comparison. by not having 'empty' terms (terms of length=0), what searches would be affected. I still haven't heard a real use case (though surely perhaps there is someone abusing this somehow), but there is a serious performance trap that is definitely real. --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
