extracting x from a point(x,y)

[Jerry Asher]

I have a table of points, actually zip codes and their points.

If a point is an X, Y pair, how do I extract X from a point? (And how
do I create or insert a new point (X, Y)?)

I am given a latitude, longitude pair and I would like to determine
the closest zipcode. I can do this using point_distance, but I wonder
if there is a faster way. If I can extract the separate x, y values
from a point, then I can define my own distance metric and that doesn
not take the square rooot.

So given a point, how do I extract the X, Y values?

Thank you,
Jerry Asher