(Quick Reference)
                version
Purpose
Used to disable optimistic locking or change the column that holds the version.
Examples
class Book {
    …
    static mapping = {
        version false
    }
}Description
Usage: 
version(string/boolean)By default GORM is configured with 
optimistic locking enabled. You can disable this by calling the 
version method with an argument of 
false:
static mapping = {
    version false
}You can pass the name to the 
version method to change the name of the database column:
static mapping = {
    version 'revision_number'
}