Re: array_length()

Peter Eisentraut <peter_e@gmx.net> writes:
> There is a tiny problem with this implementation: It returns null for an 
> empty array, not zero.  This is because array_lower and/or array_upper 
> return null for an empty array, which makes sense for those cases.  We 
> could fix this by putting a coalesce around the expression, but since 
> the array functions return null for all kinds of error cases, this might 
> mask other problems.  Or we move to a C implementation.

Basic functionality like this shouldn't be implemented as a SQL function
anyway.  People don't expect that some built-in functions should be
several orders of magnitude slower than other built-in functions of
apparently similar complexity.
        regards, tom lane