What you say is echoed by, Every incorrect assumption in this post seems to think that 1 tweet on twitter = 1 database row = "So easy!". You've left out the use

What you say is echoed by, Every incorrect assumption in this post seems to think that 1 tweet on twitter = 1 database row = "So easy!". You've left out the user fanout! One Obama Tweet = 1M database rows, someplace Assuming that is true, which I have trouble believing it is, it sounds like they need some help with normalization. I understand the tradeoffs, but it just seems crazy. Select tweet.* from tweets inner join tweeters on tweeters.id = tweets.tweeterid inner join followers on followers.followerid=loggedinuserid and followers.followee=tweet.tweeterid Yeah, okay, I know there are performance problems with joins, but there are performance problems with 1,000,000 inserts as well and you could cache the list of followees and do an "in" statement such as: select * from tweets where tweeterid in (cached_comma_separated_list_of_followee_ids) or whatever to improve select performance.