A database is the backbone of any IT system. As a Database Developer, I am sure you would want to prove your expertise and knowledge in your next job interview and win a role. Here is the list of top 30 DBMS Interview questions that will help you sail through. In addition, to enhance your skills you could go through SQL Tutorials and Top 50 SQL Interview Questions as SQL is an integrated and a vital feature in a DBMS (Database Management System).
Storing data in relational models is not new. The RDBMS(Relational Database Management System) has been in vogue for decades, especially for web-based enterprise applications. The rapid increase in distributed and cloud computing, and changing expectations of data users in data storage and management, paved the way to the two most popular open source databases- MySQL and MongoDB.
Both OLAP and OLTP are online processing systems. Opposed to a batch processing system, where transaction details pile up in a stack of documents which are then registered in batches, an online processing system is one that registers ongoing transactions in real-time.
OLTP is a transaction processing system i.e. it manages transaction-based applications over the Internet. OLTP systems, for instance, are responsible for providing data to data warehouses.
When developing the schema of a relational database, one of the most important aspect to be taken into account is to ensure that the duplication is minimized. This is done for 2 purposes:
- Reducing the amount of storage needed to store the data.
- Avoiding unnecessary data conflicts that may creep in because of multiple copies of the same data getting stored.
Normalization in DBMS
Database Normalization is a technique that helps in designing the schema of the database in an optimal manner so as to ensure the above points. The core idea of database normalization is to divide the tables into smaller subtables and store pointers to data rather than replicating it. For a better understanding of what we just said, here is a simple Normalization example:
Introduction, Overview, and History
MongoDB is a powerful, highly scalable, free and open-source NoSQL based database. MongoDB was initially released approximately 9 years ago on 11th of February, 2009 and has since then achieved the position of the leading NoSQL database. The company MongoDB Inc. (New York, United States) maintains and manages the development of MongoDB. They also provide the commercial version of MongoDB which includes support also. The source code of MongoDB is available on Github.
Over the years, MongoDB has become a popular choice of a highly scalable database and it is currently being used as the backend data store of many well-known organizations like IBM, Twitter, Zendesk, Forbes, Facebook, Google, and a gazillion others. MongoDB has also caught the eyes of the open source community and a lot of developers work on various open source projects based on MongoDB. You can download MongoDB here: https://www.mongodb.com/download-center and find MongoDB documentation here: https://docs.mongodb.com/