How to find the Reserved SQL keywords in PG/EPAS ?
Using the below SQL query one can find the reserved SQL keywords in PostgreSQL/EPAS.
SELECT * FROM pg_get_keywords();
Does “ subtype” work with EPAS ?
PG/EPAS support omitting AS only for column labels that aren't any known keyword and SUBTYPE is an un-reserved keyword in EPAS - and that is the reason "SELECT now() subtype" query doesn't work. but if same being used with AS "SELECT now() AS subtype" that works. So this is a known behavior and doesn’t have any work-around apart from using the AS or double quotes.
Community PostgreSQL :
postgres=# select * from pg_get_keywords() where word like '%subtype%' ;
word | catcode | catdesc