Which data structure should I use for storing eye retina? : <p>I need to develop and application for opening/closing of main gate of my office. That application will recognize human eye retina and then open the gate if it is valid. The image of retina is to be stored in database where it matches the upcoming image with the stored images of retina in db. Also when i want to delete the data of retina of specific person from database, it should be deleted. 
In my criteria, memory usage is to be less and very fast response of time</p>

<p><strong>Which data structure should I use for this scenario?</strong></p>
