On Fri, Jan 10, 2020 at 1:38 AM Pavel Stehule <pavel.stehule@gmail.com> wrote:
>> This still leaves the question of how best to format the docs for
>> these operators. I like being able to combine all the <@ variations
>> (e.g.) into one table row, but if that is too ugly I could give them
>> separate rows instead. Giving them all their own row consumes a lot of
>> vertical space though, and to me that makes the docs more tedious to
>> read & browse, so it's harder to grasp all the available range-related
>> operations at a glance.
>
>
> I have similar opinion - maybe is better do documentation for range and multirange separately. Sometimes there are still removed operators @+
I like keeping the range/multirange operators together since they are
so similar for both types, but if others disagree I'd be grateful for
more feedback.
ok
You're right that I left in a few references to the old @+ style
operators in the examples; I've fixed those.
> If you can share TYPTYPE_RANGE in code for multiranges, then it should be 'r'. If not, then it needs own value.
Okay. I think a new 'm' value is warranted because they are not interchangeable.
>> I experimented with setting pg_type.typelem to the multirange's range
>> type, but it seemed to break a lot of things, and reading the code I
>> saw some places that treat a non-zero typelem as synonymous with being
>> an array. So I'm reluctant to make this change also, especially when
>> it is just as easy to query pg_range to get a multirange's range type.
>
>
> ok, it is unhappy, but it is true. This note should be somewhere in code, please
I've added a comment about this. I put it at the top of DefineRange
but let me know if that's the wrong place.
The attached file is also rebased on currrent master.
Can be nice to have a polymorphic function
multirange(anymultirange, anyrange) returns anymultirange. This functions should to do multirange from $2 to type $1
It can enhance to using polymorphic types and simplify casting.
Usage
CREATE OR REPLACE FUNCTION diff(anymultirange, anyrange)
RETURNS anymultirange AS $$
SELECT $1 - multirange($1, $2)
$$ LANGUAGE sql;
when I tried to write this function in plpgsql I got
create or replace function multirange(anymultirange, anyrange) returns anymultirange as $$
begin
execute format('select $2::%I', pg_typeof($1)) into $1;
return $1;
end;
$$ language plpgsql immutable strict;
ERROR: unrecognized typtype: 109
CONTEXT: compilation of PL/pgSQL function "multirange" near line 1
So probably some support in PL is missing
But all others looks very well
Regards
Pavel
Thanks!
Paul
