NoSQL Interview Questions and Answers

There are a few disadvantages available with NoSQL database and they are as follows:

• As this is a new database storage system in the market, there are several other database system already in use
• It does not ensure round the clock support rather than other database system
• As it a new technology, it does not support any old commands

The main advantages of graph database are as follows:

• Graph database is highly preferred to implement successful networking applications
• It can also support any of the object-oriented system with high efficiency

Some of the cons that are associated with the graph database are as follows:

• Graph database is highly not recommended for network partitioning as it involves huge interconnectedness among the various nodes available
• It can be easily and efficiently scaled as per business needs

Distributed key value databases that are designed to ensure highly scalable and reliable data are known as NoSQL database management system. There is several data storage present along with various configurable sets which can be defined as the storage nodes in which data are stored in the form of key value pairs. It ensures several methodologies to store and retrieve data in the form just different from tubular method which is utilized in relational database.

The process of retrieving in NoSQL database is handled effectively with the help of Oracle database external table functions and so it is highly considerable to execute some of the queries from the Oracle database and extract or retrieve data records from the NoSQL database at ease.

Polyglot programming was first established by Neal Ford in the year 2006 with an aim to create applications with a mix up of various programming languages to underline the fact that different programming languages are used in real-time to handle various complexities.

Every application comes with different complexities and each complex problem can be resolved and made perfect with a particular language and it is not possible to resolve or handle all the complexities within a single language. For instance, let’s take an e-commerce store where the functionality of cart is totally different from searching for a product and so both requires different language to make it effective, this is the main motive or objective of “Polyglot Persistence” too.

Replication node is the type of node that manages the data that are stored in the NoSQL database and it is also known as the memory consumer. The performance is calculation with the help of the java heap and the cache size that are found in the replication node. And, these two factors are calculated by NoSQL by means of memory that is available to a specific storage node where the specification for the memory of the storage node is highly required. If the storage node has more than one replication node, then the memory will be evenly scattered among the various replication node present.

In the year 2000, Eric Brewer discovered the CAP theorem which provides three main benefits to the NoSQL database management system and they are as follows:

Consistency – Through this benefit, every node can view the same data at a single point of time.

Availability – Every request will get an instant response whether it will become successful or not.

Partition Tolerance – This benefit is actually highly crucial as it will continue the work even if some of the practices or in error or if it is not working.

This is one of the most awaited characteristics which stood as an essential preference by most of the Analysts, Developers and Big Data Architects. The main function of “Tunable consistency” is that is synchronizes and keeps all the data rows on their respective replicas up to date. This consistency level can be opted by the users as per their preference and requirement. There are two types of consistencies present in Cassandra namely – Strong consistency and Eventual consistency.

Once all the service logics in a system are executed them the system will be moved to a consistent state which is denoted as the eventual consistency in NoSQL. This concept is highly used in distributed system to achieve maximum availability. In case a data item is not updated with any recent values, then the previously updated value will be displayed as the result. Nowadays, most of the present applications are developed in accordance with the eventual consistency feature of NoSQL database.