Postgres 9.2 under FreeBSD 8.4 - How do I find the databases & tables?
Don't mess with the data files in the filesystem it's a sure way to get your database corrupted.

You can achieve what you want, by creating a tablespace and then move the table to the new tablespace:

create tablespace big_one LOCATION '/path/to/other/spindle';
alter table map_data set tablespace big_one;
commit;



Btw: MySQL isn't "more straightforward" - it's just different. And I could list several things that are much more "straightforward" in Postgres than in MySQL