I'm building a site for a client. They need a functionality where WordPress can tell if a logged in user has viewed a post in order that they might serve a notice or hide the original content.
I have never needed to do this before but am weighing up two approaches. Is it better to:
Add a column in the user table that asks which post IDs each user has viewed? A similar approach to this article: http://www.kylejlarson.com/blog/2013/how-to-create-a-wordpress-database-table/
Add some kind of meta data to the post with a list of users who have viewed a post? (I'm not even sure this is possible)
I also can't decide what the WordPress way of doing this is. A table level approach seems more intuitive to me but I've never had to implement a feature like this before so I wanted to get some advice.
Any comments/thoughts greatly appreciated.