Re: Why are no NEGATORS defined in the standard operators

Hello

On 11/06/2016 10:00, Daniel Migowski wrote:
> Hello,
>
> while trying to bake my own fixedpoint datatype I noticed the definition
> for =(int8,int8) to be
>
>
>
> CREATE OPERATOR =(
>
>   PROCEDURE = int8eq,
>
>   LEFTARG = int8,
>
>   RIGHTARG = int8,
>
>   COMMUTATOR = =,
>
>   RESTRICT = eqsel,
>
>   JOIN = eqjoinsel,
>
>   HASHES,
>
>   MERGES);
>
>
>
> in PostgreSQL 9.5, but I wonder, why there is no NEGATOR clause defined
> here? According to the docs it should help to add
>
>
>
>   NEGATOR = <>
>
>
>
> In query optimization. Is there some reason for it? Or is it a Bug in
> pgAdmin III that the negator is not shown?
>

I guess this is a bug in pgAdmin3, because the negator is defined in the
catalog:

# select o1.oprname, o1.oprcode, o1.oprnegate, o2.oprname as negate from
pg_operator o1 join pg_operator o2 on o1.oprnegate = o2.oid where
o1.oprname = '=' and o1.oprleft = 'int8'::regtype and o1.oprright =
'int8'::regtype;

 oprname │ oprcode │ oprnegate │ negate
═════════╪═════════╪═══════════╪════════
 =       │ int8eq  │       411 │ <>
(1 row)



--
Julien Rouhaud
http://dalibo.com - http://dalibo.org