I spent several days exploring the pros and cons of mysql versus nosql solutions (especially mongodb ) for my project.
The project should be able to ultimately scale the processing of tens of thousands of concurrent users - a total of millions of users. The site is highly user-oriented and will interact with the database so much, if not more than a site, such as facebook - it is very relational, all functions depend on the relationship with the user and their relationship with other users. It is also heavy data - lots of files, images, audio, messages, personal news, etc.
I like the look of mongodb , I like the way it works, and I like the way it scales, but can't figure out how it will work on the site, for example, I describe. Should all interactions for a specific user be stored in one document?
However, it is very convenient for me to use mysql as a relational aspect of this. I'm just worried without a lot of work, there will be problems with scalability with this project - although perhaps with memcached and sharding this will not be a problem?
I would like to know those who have experience with two databases for large projects, from mysql and mongodb , which is the right tool for this particular job?
user623520