usage of database model for my site

Question

I am building a social networking site. i hope for some high traffic in it. i am using php and mysql in it. i already started with RDBMS kind of database. I read that many high traffic sites use key value database model. In my situation which one should i go for ? and i guess it would be better to decide it at this early stage itself

Answer 1

For now, stick with MySQL in a traditional RDBMS format if that is what you are most familiar with. Getting your site up and running as fast as possible is WAY more important than worrying about scale issues at the 1st stages of building a site.

That being said, it doesn't hurt to keep scale concerns in mind as you design parts of the system. MySQL is already very good at some basic scaleability pieces, such as sharding, so you will probably be just fine for quite a while. Having a good DB design, with plenty of indexes, will also keep you running if you do hit sufficiently high traffic levels.

Since you expect high traffic volume (don't we all?), I would highly suggest logging / tracking the load on your server so that you can measure the actual traffic and determine if you truly do need to scale (up or out are both good options depending on the load characteristics)

Answer 2

I think it would be good if you had the key value tables for relationships between friends. For example person a could have 500 friends and person b could have 100. That means that to prevent duplicated data being copied over and over again in one table, you would get the id of the person one and id of the his friends and put them in a table. This will result in faster searches and inserts and updates because your are working with integers.

E.g

table friends_relationship id - friend 1 - 2 1 - 3 2 - 4 3 - 4

you need to make sure that the relationships are unique