st 9. 12. 2020 v 22:59 odesÃlatel Tom Lane <t...@sss.pgh.pa.us> napsal:
> Here's a couple of little finger exercises to move this along a bit. > > 0001 adds the ability to attach a subscript handler to an existing > data type with ALTER TYPE. This is clearly going to be necessary > if we want extension types to be able to use this facility. The > only thing that I think might be controversial here is that I did > not add the ability to set pg_type.typelem. While that'd be easy > enough so far as ALTER TYPE is concerned, I'm not sure that we want > to encourage people to change it. The dependency rules mean that > the semantics of typelem aren't something you really want to change > after-the-fact on an existing type. Also, if we did allow it, any > existing SubscriptingRef.refelemtype values in stored views would > fail to be updated. > > 0002 makes use of that to support subscripting of hstore. I'm not > sure how much we care about that from a functionality standpoint, > but it seems like it might be good to have a contrib module testing > that extensions can use this. Also, I thought possibly an example > showing what's basically the minimum possible amount of complexity > would be good to have. If people like this, I'll finish it up (it > lacks docs) and add it. > +1 using subscripts for hstore is nice idea Pavel > regards, tom lane > >