On Wed, Jan 13, 2010 at 05:03:33PM -0500, Robert Haas wrote: > On Wed, Jan 13, 2010 at 4:47 PM, Tom Lane <[email protected]> wrote: > > > > Spelling out "primary key" would seem to be more in keeping with existing > > entries in that column, eg we have "not null" not "NN". > > > > I think this is a sensible proposal for a single-column PK, but am less > > sure that it makes sense for multi-col. The modifiers column is > > intended to describe column constraints; which a multi-col PK is not, > > by definition. > > Yeah, IIRC, MySQL shows PRI for each column of a multi-column primary > key, and I think it's horribly confusing. I wouldn't even be in favor > of doing this just for the single-column case, on the grounds that it > makes the single and multiple column cases asymmetrical. IMO, the \d > output has too many bells and whistles already; the last thing we > should do is add more.
How about spelling it as so: Table "public.test" Column | Type | Modifiers --------+---------+----------- a | integer | primary key b | integer | Indexes: "test1_pkey" PRIMARY KEY, btree (a) Table "public.test2" Column | Type | Modifiers --------+---------+----------- a | integer | primary key (compound) b | integer | primary key (compound) Indexes: "test2_pkey" PRIMARY KEY, btree (a, b) As to Tom's point that a compound primary key is a table level restriction, by definition, participating in such a key is still a restriction on what values that column can take. When introspecting someone else's schema, with a very wide table, seeing '(compound)' is a nice strong hint to go looking for the other members of the PK. Ross -- Ross Reedstrom, Ph.D. [email protected] Systems Engineer & Admin, Research Scientist phone: 713-348-6166 The Connexions Project http://cnx.org fax: 713-348-3665 Rice University MS-375, Houston, TX 77005 GPG Key fingerprint = F023 82C8 9B0E 2CC6 0D8E F888 D3AE 810E 88F0 BEDE -- Sent via pgsql-hackers mailing list ([email protected]) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
