The answer is simple: great community and good support and the proof of the pudding is in the eating: everyone uses it including Facebook, Twitter and Google (if you want to hear other opinions try follow the xaprb.com comments flow).
Yet, if you will explore the MySQL capabilities you may find out that it lucks real multi threading capabilities. its table size is limited to effective number of 50-100M rows, its SELECT performance is limited to 50 statements on a single table per second and its INSERT performance is limited to 700 INSERT statements per second (based on standard Amazon instance and InnoDB engine).
So, how can the Internet industry with dozens of thousands of SQL statements per second in a medium site use such a limited database?
The answer is simple: Use Sharding. Sharding is a method for slashing your tables into smaller ones and storing parts of the data in each one of them. There are several common strategies including:
- Vertical Sharding: Tear a table into two, store only few columns in first table and the rest in the second table.
- Horizontal Sharding: Place each group of rows in another table. Horizontal Sharding can be implemented using various algorithms that include static hashing, hashing with directory mapping, key based directory mapping and signature based mapping.
In the last year several new COTS Sharding products were introduced to the market. These products use two mechanisms in order to get over the MySQL limitations:
- Gizzard and ScaleBase (founded by Industry experts Doron Levari and Liran Zelkha) use the MySQL Proxy mechanism in order to implement a load balancing and Sharding solutions in front of regular MySQL databases.
- Xeround and Akiban implemented a new type of storage engine based on the MySQL Storage engine API.
Will MySQL remain an Internet standard in the future?
MySQL will keep being an Internet standard, unless unexpected decisions will be taken by Oracle that owns the firm. Unwise marketing decision could harm the community and may cause a major shift to other solutions including NoSQL.
If you have a great internet idea, you have all the needed tools to start.