CREATE FUNCTION varfunc (fixed1 text, VARIADIC vars text[]) [...]
SELECT varfunc('text fixed 1'); -- error: function signature not found;
thus the number of supplied variadic values must be >= 1
This:
http://www.postgresql.org/docs/9.4/static/xfunc-sql.html
Describes how to invoke a function defined with VARIADIC with an actual
array as input instead of supplying ONE-or-more individual arguments to the
call.
AFAICS the only way to get the called function to see an empty array is to
call it like:
SELECT varchar('text fixed 1', VARIADIC ARRAY[]::text[])
While this is a logical solution to the problem, given the above knowledge,
it would be nice if both points were made explicitly in the documentation
in the section linked above.
Existing: "Sometimes it is useful to be able to pass an already-constructed
array to a variadic function; this is particularly handy when one variadic
function wants to pass on its array parameter to another one."
Change that to:
"Sometimes it is useful to be able to pass an already-constructed array to
a variadic function."
<move existing sample to here>
"While this is particularly handy when one variadic function wants to pass
on its array parameter to another[/cut] it is required if you wish to
invoke the function without passing any optional arguments. The following
example's first attempt to omit the variadic argument fails since the
planner looks for a different function signature. By using the variadic
invocation the second attempt succeeds. The alternative is to define an
overloaded function without a VARIADIC parameter but with the same
non-optional ones."
<better example maybe...but show/explain the two queries above>
Thoughts? Am I missing something?
David J.
