2011/1/10 Tom Lane <t...@sss.pgh.pa.us>: > There was never any intention that that code produce a guaranteed-unique > identifier; it's only meant to be a humanly useful identifer, and this > patch seems to me to mostly add noise.
For all objects, except for these pg_amproc regclass, the function does already generate unique strings. They are guaranteed to be unique thanks to every component of the unique constraints in alll pg_* tables are included in the unique text identifier. It makes a lot more sense to fix the function to return a unique string also for pg_amproc, than to introduce a entirely new function which returns a unique string identifier. It would hardly break anything and I think you exaggerate the noise factor. I can think of numerous reasons why it is absolutely necessary to provide a function generating unique identifiers for objects: a) To allow comparing all objects in two different databases, by comparing objects with the same identifier. This cannot be done using the oids, since they naturally differ between databases. b) To draw nice human readable digraphs in the .dot format , instead of drawing relations digraphs of classid.objid.subobjid. c) OIDs are probably misused in a lot of applications, due to misunderstandings of what they are and not are, I for one didn't know they are not necessarily unique, but only within their regclass. It would be better to encourage users to use a text string if they need to refer to a unique objects in their application, than to force them to use OIDs (or in combination with the regclass, almost as bad), in lack of something better. While you could build your own query to generate a unique string, based on all the columns defining the unique constraint for each class, doing so is very cumbersome and requires a lot of postgres-guru-knowledge. I think it would be a big improvement and increase the number of possible use cases of the existing pg_describe_object function if the documentation would say "the returned text is guaranteed to be unique for each object". -- Best regards, Joel Jacobson Glue Finance E: j...@gluefinance.com T: +46 70 360 38 01 Postal address: Glue Finance AB Box 549 114 11 Stockholm Sweden Visiting address: Glue Finance AB Birger Jarlsgatan 14 114 34 Stockholm Sweden -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
