Heikki Linnakangas wrote: > Oleg Bartunov wrote: > > On Wed, 8 Aug 2007, Bruce Momjian wrote: > >> Heikki Linnakangas wrote: > >>> If I understood correctly, the basic issue is that a tsvector datum > >>> created using configuration A is incompatible with a tsquery datum > >>> created using configuration B, in the sense that you won't get > >>> reasonable results if you use the tsquery to search the tsvector, or do > >>> ranking or highlighting. If the configurations happen to be similar > >>> enough, it can work, but not in general. > >> > >> Right. > > > > not fair. There are many cases when one can intentionally use different > > configurations. But I agree, this is not for beginners. > > Can you give an example of that? > > I certainly can see the need to use different configurations in one > database, but what's the use case for comparing a tsvector created with > configuration A against a tsquery created with configuration B?
I assume you could have a configuration with different stop words or synonymns and compare them. > >>> - using an expression index instead of a tsvector-field, and always > >>> explicitly specifying the configuration, you can avoid that problem (a > >>> query with a different configuration won't use the index). But an > >>> expression index, without explicitly specifying the configuration, will > >>> get corrupted if you change the default configuration. > >> > >> Right. > > > > the same problem if you drop constrain from table (accidently) and then > > gets surprised by select results. > > The difference is that if you change the default configuration, you > won't expect that your queries start to return funny results. It looks > harmless, like changing the date style. If you drop a constraint, it's > much more obvious what the consequences are. > > > We should agree that all you describe is only for DUMMY users. From > > authors point of view I dislike your approach to treat text searching as > > a very limited tool. But I understand that we should preserve people > > from stupid errors. > > > > I want for beginners easy setup and error-prone functionality, > > but leaving experienced users to develop complex search engines. > > Can we have separate safe interface for text searching and explicitly > > recommend it for beginners ? > > I don't see how any of the suggestions limits what you can do with it. > If we remove the default configuration parameter, you just have to be > explicit. If we go with the type-system I suggested, you could still add > casts and conversion functions between different tsvector types, where > it make sense. I don't think the type system is workable given the ability to create new configurations on the fly. I think the configuration must be specified each time. At this point, if we keep discussing the tsearch2 API we are not going to have this in 8.3. -- Bruce Momjian <[EMAIL PROTECTED]> http://momjian.us EnterpriseDB http://www.enterprisedb.com + If your life is a hard drive, Christ can be your backup. + ---------------------------(end of broadcast)--------------------------- TIP 7: You can help support the PostgreSQL project by donating at http://www.postgresql.org/about/donate