Question

I’m building a private social network with Yii that will have “comments” all over the site – in Profiles, Events pages, Group Threads, etc. When a user makes a post, they will be able to select the visibility of that content as:

• Anyone
• Registered Users Only
• Friends Only
• Custom (specific list of friends)

I’m trying to figure out how to model this for speed. I’ve considered using MySQL for writing the setting into a binary “is_secure” field in the Comments table – if it is true, then go to a table with three columns: comment_id, user_id, and group_id. Groups (group_id) would be for groups of users – Registered Users, Friends. Custom would make one row for each user that is selected (user_id).

This table will get huge (perhaps several dozen rows for each comment), so I’m wondering if using NoSQL is worth considering here for retrieval only, or if there’s a better way to model this.

Thanks so much!

Answer 1

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Instead of an IF true/false with the is_secure field, just add 1-bit fields for read_all (anyone), registered, friends, custom. Add another table which holds the custom list would have comment_id (from the previous table) and friend_id (multiple rows). That way, in a single query with a LEFT JOIN on custom_friends_list_for_comments you can determine whether or not to show the page to a user. Optionally, custom could be a comma separated list (char field) but size limits might be an issue. Assuming 3-letter friend ids with a comma, each 255 char field can have 64 friends.