On Apr 1, 2009, at 2:22 PM, Tom Lane wrote:
Another way to state the point is that we can offer people a choice of two limitations: string_to_array doesn't work for zero-length lists, or string_to_array doesn't work for empty strings (except most of the time, it does). The former is sounding less likely to bite people unexpectedly.
Right, very well put.
Or we could stick to the current behavior and say "use COALESCE() to resolve the ambiguity, if you need to".
Steve has a point that leaving it as-is leaves it as impossible to tell the difference between string_to_array(NULL, ',') and string_to_array('', ','). The former properly handles an unknown value, while the latter, where '' is a known value, seems weird to be returning NULL.
Best, David -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
