Barun is starting his next software development assignment soon, but his biggest worry is - SQL or NoSQL and he is pondering about these questions:
Which database to use for this new project?
Should I use relational database or NoSQL?
MongoDB is nice, it is schema-less and it does not require creating tables and normalize the structure, should I just select it for this project?
Or whether I just use cloud-native databases like Amazon DynamoDB or Cosmos DB?
No wait, I heard Redis can also be used for persistence and it is a key-value pair so that may also fit well here! The choices are endless...
Have you ever come across these questions or a debate on which database is right for your project? The decision depends on number of factors and there are dozens of articles available over internet explaining pros and cons of different options. I am not going to repeat them here. I am rather interested in documenting what some of the popular internet apps are using as their data store. I'd done this exercise in the past, but lost the record. While doing this exercise again, I thought this could be useful for wider #DEVCommunity.
It would be interesting to know from you if you have gone through the process of making decision on choosing the right data store for your application. Feel free to add your comments to build this knowledge base.
Twitter - Twitter was built on MySQL and everything was stored in a single instance of database. However, as platform evolved, it is using number of different database technologies - MySQL, PostgreSQL, Vertica, Blobstore, Graph store, Hadoop. You can read more information about this here
Facebook - MySQL, Memcached, Haystack (for photo storage), Hadoop and Hive. Read more about complete technology stack used by Facebook here
Youtube - MySQL, Bigtable
LinkedIn - traditionally used Oracle and key-value stores such as Voldemort. But then moved to distributed data store, Espresso.
DEV.together - PostgreSQL as primary datastore and Redis for cached data.
Note: this information is collected from different forums, engineering blogs and Q&A sites, if you think anything is incorrect, feel free to point out, I will be happy to update the post.