SELECT
	col.attname as column_name,
	(
		SELECT 
			pg_catalog.pg_get_expr(def.adbin, def.adrelid)
		FROM 
			pg_catalog.pg_attrdef def
		WHERE 
				def.adrelid = col.attrelid 
			AND def.adnum = col.attnum 
			AND col.atthasdef
	) as column_default,
	col.attnum as ordinal_position,
	CASE 
		WHEN typ.typcategory ='E'
		THEN 
			'enum'
		WHEN typ.typcategory='C'
		THEN
			'composite' 
		
	ELSE
		pg_catalog.format_type(col.atttypid, col.atttypmod)
	END
	AS type_format,
	(
		SELECT 
			pg_get_serial_sequence(format('%I.%I',tabsch.nspname,tab.relname), col.attname) IS NOT NULL
		FROM 
			pg_catalog.pg_class tab
			INNER JOIN pg_catalog.pg_namespace tabsch
			ON	tab.relnamespace=tabsch.oid
		WHERE
			tab.oid=col.attrelid
	) as col_serial,
	

	
	typ.typcategory as type_category,
	CASE
		WHEN typ.typcategory='E'
		THEN
		(
			SELECT 
				string_agg(quote_literal(enumlabel),',') 
			FROM 
				pg_catalog.pg_enum enm 
			WHERE enm.enumtypid=typ.oid 
		)
		WHEN typ.typcategory='C'
		THEN 
		(
			SELECT 
				string_agg(
					format('%I %s',
						attname,
						pg_catalog.format_type(atttypid, atttypmod)
					)
				,
				','
				)	 
			FROM 
				pg_catalog.pg_attribute 
			WHERE 
				attrelid=format(
					'%I.%I',
					sch.nspname,
					typ.typname)::regclass
				)
	END AS typ_elements,
	col.attnotnull as not_null
FROM 
	pg_catalog.pg_attribute col
	INNER JOIN pg_catalog.pg_type typ
		ON  col.atttypid=typ.oid
	INNER JOIN pg_catalog.pg_namespace sch
		ON typ.typnamespace=sch.oid
WHERE 
		col.attrelid = 'foo.bar'::regclass  --this is used to filter the table's name
	AND NOT col.attisdropped
	AND col.attnum>0
ORDER BY 
	col.attnum
;