Queries and Analytics

A query language constitutes a computer language that enables developers to manipulate data inside a database.

Users of relational databases launch queries using the common structured query language (SQL) standard. However, there is no standard to query NoSQL databases. Indeed, each NoSQL database has its unique way to manage, extract and query data. Consequently, data scientists face the challenge to understand the query language of each NoSQL database.

On the contrary, SQL databases are powerful to handle complex queries through a standardised interface. However, NoSQL databases lack performance when dealing with NoSQL databases for big data 175

complex queries. Joints are difficult to achieve in NoSQL databases. Instead, NoSQL are more adequate to handle parallel computations and mathematical equations on distributed large and evolving datasets.

Compared to RDMS, NoSQL solutions are less suitable for business intelligence use cases. This is because NoSQL are usually complex to use for advanced analytics complex queries and joins, as mentioned before.

Security

In general, relational databases incorporate secure mechanisms. However, they are still facing many security risks such as SQL injection, cross site scripting, root kits, and weak communication protocols.

Certainly, NoSQL databases offer better scalability and flexibility. But, most NoSQL databases do not include built-in security mechanisms. So users have to deal with different security issues. Some security tools and modules have been added on the top of NoSQL databases. They constitute a very thin security layer in comparison to relational databases.

In fact, most NoSQL databases do not secure client server communications and do not provide authentication nor auditing mechanisms.

CouchDB is an example that offers auditing but it stores users’ names and passwords in logs files. This compromises data security. To ensure authentication, users are usually required to add external components to NoSQL infrastructure

Furthermore, while encryption of structured data is easier in relational databases, the encryption of very large unstructured data sources is difficult to achieve. Thus, most of such sources are stored in clear format in NoSQL.

Therefore, we can conclude that NoSQL rise many security issues because they are not mature. However, for some use cases, security is important to protect valuable, confidential or sensitive large sources (e.g., health, government, system security and so on)