MongoDB - Strength & Weakness

Mongo’s Strengths

Mongo’s primary strength lies in its ability to handle huge amounts of data
(and huge amounts of requests) by replication and horizontal scaling. But it
also has an added benefit of a very flexible data model, since you needn’t ever
conform to a schema and can simply nest any values you would generally
join using SQL in an RDBMS anyway.

Finally, MongoDB was built to be easy to use. You may have noticed the
similarity between Mongo commands and SQL database concepts (minus the
server-side joins). This is not by accident and is one reason Mongo is gaining
so much mind share from former object-relational model (ORM) users. It’s
different enough to scratch a lot of developer itches but not so different it
becomes a wholly different and scary monster.


Mongo’s Weaknesses

How Mongo encourages denormalization of schemas (by not having any) might
be a bit too much for some to swallow. Some developers find the cold, hard
constraints of a relational database reassuring. It can be dangerous to insert
any old value of any type into any collection. A single typo can cause hours
of headache if you don’t think to look at field names and collection names as
a possible culprit. Mongo’s flexibility is generally not important if your data
model is already fairly mature and locked down.


Because Mongo is focused on large datasets, it works best in large clusters,
which can require some effort to design and manage.