1. Compare MongoDB and Cassandra Criteria MongoDB Cassandra Data Model Document Big Table like Database scalability Read Write Querying of data Multi-indexed Using Key or Scan Read this blog to learn about the comparison of MongoDB & Cassandra. 2. What makes MongoDB the best? MongoDB is considered to be best NoSQL database because of :Document-oriented (DO)
NodeJS Interview Questions
Node.js is a server-side technology that you have to be proficient in to become the ideal MEAN stack developer. It is one of the most rewarding web development tools to learn, not only because of the lucrative salary—averaging $100,000/ year—but also the fast and continued growth of job postings requiring knowledge of the technology. If
AngularJS Interview Questions
What are the basic steps to unit test an AngularJS filter? (Question provided by Daniel Lamb) Inject the module that contains the filter. Provide any mocks that the filter relies on. Get an instance of the filter using $filter(‘yourFilterName’). Assert your expectations. Dependency injection is a powerful software design pattern that Angular employs to compose responsibilities through
TypeScript Interview Questions
Q1. What is TypeScript and Why Do We Need It? Ans. JavaScript is the only client side language universally supported by all browsers. But JavaScript is not the best designed language. It’s not a class-based object-oriented language, doesn’t support class based inheritance, unreliable dynamic typing and lacks in compile time error checking. And TypeScript addresses all
JavaScript Interview Questions
Explain event delegation Event delegation is a technique involving adding event listeners to a parent element instead of adding them to the descendant elements. The listener will fire whenever the event is triggered on the descendant elements due to event bubbling up the DOM. The benefits of this technique are: Memory footprint goes down because
Joins in NoSQL database
Joins are hard to do in any distributed database. Even on distributed Sql databases. It is not that joins cannot be supported in a NoSql database. It is just that the database is not designed to be efficient for joins (I’ll explain why), and hence there is no point in supporting joins. Because if you
Key-value database
A key-value database, or key-value store, is a data storage paradigm designed for storing, retrieving, and managing associative arrays, a data structure more commonly known today as a dictionary or hash. Dictionaries contain a collection of objects, or records, which in turn have many different fields within them, each containing data. These records are stored
Database optimization
While certain queries may, by their very nature, require little or no cost estimation or comparison between plans to determine optimum performance, most queries will benefit from full optimization. One of the most beneficial methods for increasing the performance of queries is the creation of efficient indexes. A well-constructed index will allow a query to
Database transaction
A transaction symbolizes a unit of work performed within a database management system (or similar system) against a database, and treated in a coherent and reliable way independent of other transactions. A transaction generally represents any change in a database. Transactions in a database environment have two main purposes: To provide reliable units of work
RDBMS architecture
The design of a DBMS depends on its architecture. It can be centralized or decentralized or hierarchical. The architecture of a DBMS can be seen as either single tier or multi-tier. An n-tier architecture divides the whole system into related but independent n modules, which can be independently modified, altered, changed, or replaced. In 1-tier
Database relationships
Database relationships are associations between tables that are created using join statements to retrieve data. The following table describes the database relationships. Type of relationship Description One-to-one Both tables can have only one record on each side of the relationship. Each primary key value relates to none or only one record in the related table.
Data integrity
Data integrity is a fundamental component of information security. In its broadest use, “data integrity” refers to the accuracy and consistency of data stored in a database, data warehouse, data mart or other construct. The term – Data Integrity – can be used to describe a state, a process or a function – and is