[Peter Eisentraut <peter.eisentraut@enterprisedb.com>]

On 19.05.22 04:12, Kyotaro Horiguchi wrote:
> At Wed, 18 May 2022 18:23:57 +0200, Peter Eisentraut <peter.eisentraut@enterprisedb.com> wrote in
>> "Boolean" is correct; see <https://en.wiktionary.org/wiki/Boolean; for
>> example.
> 
> Ok, so, don't we in turn need to replace "boolean"s with "Boolean"?
> 
> "only boolean operators can have negators"
> "only boolean operators can have restriction selectivity"
> ...
> 
> And I'm not sure how to do with "bool". Should it be "Boolean" instead
> from the point of uniformity?
> 
> errmsg("only bool, numeric, and text types could be "

The SQL data type is called BOOLEAN, and we typically lower-case type 
names in PostgreSQL, so messages should be like

     column %s should be of type integer
     column %s should be of type boolean

As an adjective, not a type, it should be spelled Boolean, because 
that's how it's in the dictionary (cf. Gaussian).

     %s should have a string value
     %s should have a Boolean value

"bool" should normally not appear in user-facing messages, unless we are 
dealing with internal type names (cf. int4) or C types.

Of course, the lines between all of the above are blurry.