What is the most scaleable and efficient way of managing profile pics
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I know this question has been asked many times before, but I haven't found an answer that addresses my specific case.

Using PHP & MySQL...

I'm about to add user profile pics to an app and as I see it I have several options. Two of which are as follows:

 


 **1.** Make no reference to the image in the database and store the images
    like so:-

     

 - /assets/avatars/32px/userid.jpg
       
 - /assets/avatars/90px/userid.jpg
 - /assets/avatars/256px/userid.jpg

This would mean no extra database lookups as  I will already have the relevant userid.


 **1.** Store the relative path in the users_meta table and retrieve the url's using a join when I retrieve user data.


What are the pro's con's of each method?  And if in your opinion, neither method is the best way, what would you consider to be the most efficient and scaleable way of storing/referencing and retrieving user profile pics.

Many thanks