There is a mention of UserPhoto table but I don’t see it being used in design as after getting the follows from UserFollows it directly hits the metadata table Photo.
Also if you just have an index on PhotoId how do you plan to find the user. As flow says
- first you find all users which a user follows
- then get the posts for these users so there is a filter on user as well and if we don’t have index on user in metadata table then this would be a full scan.