There is articles on Hacker News a few days ago that arrived at first page entitled something similar to
"2 times when to not use Mongodb" however i really aren't able to find it any longer...

  1. Does anybody know where I'm able to discover the above referred to article?
  2. What cases exist when NoSQL fails?

By any reasonable definition "NoSQL" needs to include non-SQL RDBMSs in the scope (due to there being no seem reason the relational model can't address exactly the same needs as other NoSQL models). Should you believe that, then there's no limit as to the NoSQL DBMSs could do. We'd don't have any more necessity of SQL - ever!

Sadly, there appears to become a common assumption among NoSQL thought leaders that "NoSQL" needs to mean "not relational". That's highly unfortunate if the relational model is overlooked then NoSQL isn't prone to replace SQL for a lot of reasons. (I become complacent that getting a lengthy-term, relational model alternative for SQL would really be considered a positive thing :)

You won't want to use NoSQL typically whenever you....

... don't wish to use SQL! /sturdy har har

The majority of the NoSQL solutions I have seen appear to fall within the key-value store approach, and aren't relational. They have a tendency to stop Acidity qualities.

Then when you evaluate a database system, whenever you don't need Acidity, whenever you don't want relational algebra, whenever you do need to have a KV store, then your NoSQL approach is the friend.

Note too that there's a multitude of 'NoSQL' systems, and all of them are busily focusing on slightly different approaches.