I am building a website with Asp.Net MVC 4 and C#, hosted in VPS. The site has lots of sharing comments/replies features (I need to store a lot of comments). I was planning to use MongoDB as its free and also very suitable for storing blogs/comments, but got a little hesitant after I read this article.
So now I am thinking of using MongoDb for storing comments and replies and SQL Server Express version with 10GB limitation for storing user accounts and other user profile data.
Is it okay to use 2 different databases like this in one web app? Or is there any other stable documents database similar to MongoDb that I can use and don’t have to use SQL server ?
Is RavenDb an option ?
Thanks in advance !
Yes, it is okay to use two different databases in one web app. Even more – it’s very good to do so, as every type of database has it cons and pros and they are never fit to do every job. You’ve probably chosen MongoDB because you’ve heard it’s quite good for storing lots of data and heavy quering. This is mostly true but there are some caveats. On the other hand, SQL Server can be much slower (depends on exact workflow), and can be easily overloaded with heavy writes.
First of all – it does work well. Mostly. It tries as hard as it can, when on heavy load. But it’s not as write efficient with parallel writes (because of heavy use of locking) as some others and it’s not “very-safe” if you have to keep some collections or documents synchronised – e.g. SQL transaction, that does lots of stuff in different tables, as mongo does not give you anything more than document-level transactions (every change on single document is atomic).
There are other stable documents database, e.g. look at CouchDB – it’s more write-oriented and has some funny possibilities thanks to Multi-Version Concurrency Control.