Question

Suppose A follows 100 person,

then will need 100 join statement,

which is horrible for database I think.

Or there are other ways ?

Answer 1

Why would you need 100 Joins?

You would have a simple table “Follows” with your ID and the other persons ID in it…

Then you retrieve the “Tweets” by joining something like this:

Select top 100 
    tweet.* 
from 
    tweet 
inner join 
    followers on follower.id = tweet.AuthorID 
where 
    followers.masterID = yourID

Now you just need a decent caching and make sure you use a non locking query and you have all information… (Well maybe add some userdata into the mix)

Edit:

tweet

ID - tweetid
AuthorID - ID of the poster

Followers

MasterID - (Basically your ID)
FollowerID - (ID of the person following you)

The Followers table has a composite ID based on master and followerID
It should have 2 indexes – one on “masterID – followerID” and one on “FollowerID and MasterID”