John R Pierce wrote
> a difficulty of the single entry for joe<->bob is that its hard to have
> a unique constraint across two fields. you'd want to ensure that
> joe+bob is unique and that there's no bob+joe
Bill's solution:
PRIMARY KEY (person1, person2),
CHECK (person1 < person2)
seems to make this constraint fairly simple...am I missing something?
Usage need permitting how difficult would setting up materialized views to
maintain arrays of "friend_of" and "friends_are" and simply unnest those
arrays if record-oriented access to the contained ids is required? More
basically how performant (generally) are ~200 element arrays?
David J.
--
View this message in context: http://postgresql.nabble.com/Modeling-Friendship-Relationships-tp5826592p5826608.html
Sent from the PostgreSQL - general mailing list archive at Nabble.com.