SQL question

Hi List;

I have a table that has 3 date columns :

create table xyz (
xyz_id integer,
date1   timestamp,
date2   timestamp,
date3   timestamp
)


I want to select in a query the xyz_id and the max date column for  
each row
something like :
create table temp2 as select xyz_id (max date?) where ...

Is this - the (max date?) part a case scenario or is there a better,  
more efficient method ?

Thanks in advance