I thought I'd try storing latitude and longitude coordinates (in decimal degrees) using reals. Using phppgadmin, I entered:
latitude:44.353333
longitude: -68.283056
However, after saving the record, Postgres stored the values as:
latitude: 44.3533
longitude: -68.2831
Postgres rounds reals? I figured it'd give an error as with most/all other data types. (nevermind - Rounding may take place if the precision of an input number is too high) The docs also say that reals should have at least 6 decimal digits of precision (the values stored have only 4). I've never really used reals - have never found a use for them. I use numeric instead (if decimal places are needed).
update - IIRC the 6 decimal digits isn't decimals only, but six consecutive digits. Hmm, maybe I'll use doubles instead, or numerics. I don't see anything in the geometric data types that appears suited to latitude and longitude (PostGIS (and perhaps something in contrib) likely does though).
