>> I think it's actually more correct to say that {} has an undefined >> number of dimensions. > > That is your opinion, but not my argument above.
I'm aware of that. I believe that the semantics of array operations should carry more weight than a count of curly braces, but certainly you don't have to agree. >> But {}, and ONLY {}, can be concatenated with an array of any number >> of dimensions. > > Which doesn't necessarily make much sense ... Well, we could change it, which would render the argument about the current semantics of {} moot. The obvious thing to do would be create separate empty arrays of dimensions 1, 2, 3, 4, 5, and 6, say '{}'::int[], '{{}}'::int[], etc. This would break backward compatibility for people using multi-dimensional arrays, but that might not be that many people. (Dunno.) Alternatively, we could make separate types int[], int[][], int[][][], etc. Then '{}'::int[] would be an empty one-dimensional array, '{}'::int[][] would be an empty two-dimensional array, etc. ...Robert -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers