On 2014-06-09 13:42:22 +0200, Vik Fearing wrote: > On 06/09/2014 09:06 AM, Gavin Flower wrote: > > From memory all unique keys can be considered 'candidate primary keys', > > but only one can be designated 'the PRIMARY KEY'. > > Almost. Candidate keys are also NOT NULL.
The list actually is a bit longer. They also cannot be partial. There's generally also the restriction that for some contexts - like e.g. foreign keys - primary/candidate keys may not be deferrable.. Greetings, Andres Freund -- Andres Freund http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
