(Quick Reference)
                fetch
Purpose
Configures the fetching behavior of an association.
Examples
class Author {    static hasMany = [books: Book]    static mapping = {
        books fetch: 'join'
    }
}Description
Usage: 
association_name(fetch:string)Arguments:
- fetchStrategy- The fetching strategy to use. Either- joinor- select.
By default GORM assumes fetching of associations is done using a 
SELECT when the association is accessed. If you prefer that the association be fetched eagerly at the same time then you can override the behavior:
class Author {    static hasMany = [books: Book]    static mapping = {
        books fetch: 'join'
    }
}Here the 
books association will be fetched using a join at the same time the author is retrieved, for example:
def author = Author.get(1)
// the books collection is pre-initialized - no risk of lazy loading exceptions
Note that excessive use of joins can be a performance bottleneck. See the section on 
Eager vs Lazing Fetching in the user guide.