count function alternative in postgres - Mailing list pgsql-general

Is there any alternative of mysql function COUNT(DISTINCT expr,
[expr...]) in postgres. We get error if we

write count like this count(distinct profile.id, profile.name,
profile.age) but it works well in mysql.

Reference url is given below

http://dev.mysql.com/doc/refman/5.1/en/group-by-functions.html#function_count-distinct

Thanks