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