SQL Server: Friends class "facebook like"

I need that 1 User can be friend of other user. So I think that I can use 2 table:

• table User (Id, Name, Date, Etc.)
• table Friends (UserId, Friend_UserId)

With these tables, I can match that 1 user is friend of other user. The 开发者_如何转开发problem is that for 1000 user, there are 1000*1000 = 1.000000 or rows.

I don't know how much row can be stored in SQL Server, but my question is what happened for 1 milion of users? SQL Server go in crash?

Anyone can share experience about Friends-Class (in the OOP concept I remember that this was the name)!

in your example 1000*1000 means every user is friends with everyone. Why store the associations at all?

Is that really going to be the case? Or are you just testing the theoretical limit?

And are you going to store two copies of every association? Say user 1 and User 2 are friends. Are you going to have a table with both of these rows:

UserId, Friend_UserId
1           2
2           1

That would double the amount of data needed. You should make it a rule that the lower of two ID's is always in one column.

And of course, make sure you index both columns.

You can store 1000 users and friend on a server, you can store 10000 users and friends on a server, you can store maybe 1M users and friends on a server, but for sure you won't be able to store 100M users and friends and have any decent latency for responses that write/read the DB. With social web-scale apps there is simply no single box that can handle a successful app. This is why the name of the game is scale-out and sharding. You can choose to and get real and ignore the problem for now. Or you can choose to design a for it. Also, see Sharding With SQL Azure and is worth reading into other alternatives.

One of the many reasons behind a good SQL server is specifically holding, and querying, many rows. There is no problem (beyond maybe physical server resources, such as HDD space) that will prevent 1,000,000 rows in a table.

but my question is what happened for 1 milion of users? SQL Server go in crash?

Yes, if you run it on your mobile phone.

Run it on apprpriate hardare nad it can eashily handle hundreds iof billions of rows in a table. Data warehouse projects do that all the time.