On Pavel's page is the following function:

CREATE OR REPLACE FUNCTION makedate(year int, dayofyear int)
RETURNS date AS $$
SELECT (date '0001-01-01' + ($1 - 1) * interval '1 year' + ($2 - 1) * interval '1 day'):: date
$$ LANGUAGE sql;

I have the following code:

makedate(y.year,1)

What is the fastest way in PostgreSQL to create a date for January 1st of a given year?

Pavel's function would lead me to believe it is:

date '0001-01-01' + y.year * interval '1 year' + interval '1 day';

My thought would be more like:

to_date( y.year||'-1-1', 'YYYY-MM-DD');

Am looking for the fastest way using PostgreSQL 8.4. (The query that uses the date function can select between 100,000 and 1 million records, so it needs speed.)

Thank you!