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.
> 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. best regards, Florian Pflug -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
