Franco Bruno Borghesi <franco@akyasociados.com.ar> writes:
> This makes me wonder, what about 't' and 'f'?... will they disappear in
> newer versions of postgreSQL?
No. See my comment about I/O representations being outside the spec.
There is no inconsistency in the following examples:
regression=# select true;
bool
------
t
(1 row)
regression=# select t;
ERROR: attribute "t" not found
regression=# select 't'::boolean;
bool
------
t
(1 row)
regression=# select '1'::boolean;
bool
------
t
(1 row)
regards, tom lane