2010/12/15 Pavel Stehule <pavel.steh...@gmail.com> > 2010/12/15 Dmitriy Igrishin <dmit...@gmail.com>: > > > > > > 2010/12/15 Florian Pflug <f...@phlo.org> > >> > >> On Dec15, 2010, at 18:33 , Dmitriy Igrishin wrote: > >> > 2010/12/15 Florian Pflug <f...@phlo.org> > >> > On Dec15, 2010, at 16:18 , Dmitriy Igrishin wrote: > >> > >> 2010/12/15 Florian Pflug <f...@phlo.org> > >> > >> On Dec15, 2010, at 02:14 , James William Pye wrote: > >> > >> > On Dec 13, 2010, at 6:16 PM, Tom Lane wrote: > >> > >> >> how do you identify which type OID is really hstore? > >> > >> > > >> > >> > How about an identification field on pg_type? > >> > >> > > >> > >> > CREATE TYPE hstore ..., IDENTIFIER 'org.postgresql.hstore'; > >> > >> > -- Where the "identifier" is an arbitrary string. > >> > >> > >> > >> I've wanted something like this a few times when dealing > >> > >> with custom types within a client. A future protocol version > >> > >> might even transmit these identifiers instead a the type's OID, > >> > >> thereby removing the dependency on OID from clients entirely. > >> > > > >> > > In some another tread I've proposed CREATE TYPE ... WITH OID... > >> > Yeah, and I believe type identifiers are probably what you were > >> > really looking for ;-) > >> > Indeed, but why OID cannot serve as identifier in this case ? Why to > >> > encode the code ? :-) > >> Because there are only 2^32 OIDs, so if people start picking them at > >> random, sooner or later there will be collisions. > > > > Yes, but range of PostgreSQL's OIDs can be reserved. One or even ten > > millions, e.g. can be enough. > > > >> > >> > Type identifiers would solve > >> > this, by providing an easy and unambiguous way to find specific types. > >> > Agree with 1st assertion but disagree with 2nd. If I understand > >> > correctly, > >> > "identifier" is a second name for type (object), but Java-styled, > right > >> > ? > >> > It probably does solve the problem if there are will be convention > that > >> > types org.postgresql.* are reserved. > >> Yeah, that'd be the idea. If everyone uses reversed DNS-style names, and > >> everyone picks a name belonging to a DNS zone under his control, there > >> cannot be any collisions. At least for java packages, this seems to work > >> pretty nicely. > >> > >> > But why not reserve name of type > >> > "hstore" and prevent the user to create type with this reserved name ? > >> > All this tells me one thing - to avoid conflicts of naming of specific > >> > types > >> > it is necessary to make them built-in. > >> None of these solutions scale well. > > > > Well, If there are will be identifiers for each type, e.g. > > org.postgresql.integer, why > > they need to be built-in ? For "historical reasons" ? :-) > > Let them also be in contribs... > > some types are used in system tables, so without support of these > types, then you can't to add a new types. It's a egg-chicken problem > So, the formal criterion to make the type built-in is "the type is must be primitive" ?
> > Pavel > > >> > >> best regards, > >> Florian Pflug > >> > >> > > > > > > > > -- > > // Dmitriy. > > > > > > > -- // Dmitriy.
