Default Duration In Coutputcache

COutputCache::duration property:

In this code if we don’t define the duration property the content as default regenerate each 60 seconds?


	beginCache('categoriesMenu',array('dependency'=>array(

		'class'=>'system.caching.dependencies.CDbCacheDependency',

		'sql'=>'SELECT unix_timestamp(MAX(update_date))+count(*) FROM category',

	)))): ?>

I think due we have an dependency, until this dependency is valid duration is not matter. Do i think right?