question about "use MODULE"

[MMKHAJAH]

Hello,
 I wonder wether 'use module' compiles only once. I mean that all sebsequent calls 
don't involve compiling. 

Example:
MyLib.pm

package MyLib;
use strict;
use MyConfig;

##
## Code the uses MyConfig
##

MyScript.pl
use MyLib;
use MyConfig;

Will the 'use MyConfig' in the second file compile again?

Thanks in advance