Table creation takes too much time

Hi,

I try to create a table with the command
create table t1 as select .... from.... where.....
It takes few hours. If I run only the sql statemen in this create table command - select .... from.... where.....,

it takes just few minutes. Few tables are used in this statement, from local and remote databases and I join them.

Why there is some huuuge difference between create table...
and slone select? Is there way to speed up table creation, as the required data actually is returned and awailable just for few minutes.

Thanks and regards,