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Ans. Relational Database uses linear search if we don't query using indices. Performance for linear search is O(n). If indices have been used , relational database uses binary search. Performance for binary search is O(Log n).
Casandra uses hash search. Performance for Hash Search is O(1).
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Ans. Normalization is the process of splitting one Table into multiple so as to avoid Data duplication whereas Denormalization is the process of reducing Tables that creates data duplication but would remove joins in the queries.
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Ans. We are using EC2 and Lambda for computing, RDS for Database , S3 for Storage , SQS and Kinesis for streaming and queue and CloudWatch for monitoring.
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Ans. We can have 2 entities i.e EMPLOYEE and ADDRESS and can have a relationship Table , EMPLOYEE_ADDRESS having one to may relationship between the two.
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Ans. There is no concept of de referencing with primitive types and hence they are implicitly immutable. Having wrapper classes as mutable offers disadvantages compared to primitive types. Wrapper classes being immutable offer similar advantage as primitive types.It actually overshadows the disadvantage wrapper class could have if they are immutable.
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Ans. Immutable objects are thread-safe so you will not have any synchronization issues.Immutable objects are good for Map keys and Set elements, since these typically do not change once created.Immutability makes it easier to write, use and reason about the code (class invariant is established once and then unchanged)Immutability makes it easier to parallelize your program as there are no conflicts among objects.The internal state of your program will be consistent even if you have exceptions.References to immutable objects can be cached as they are not going to change.
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Ans. Here are the differences between Agile and Waterfall Methodology:
The software development process is divided into different phases in the Waterfall model while Agile methodology segregates the project development lifecycle into sprints
Waterfall is a structured software development methodology, and often times can be quite rigid, whereas the Agile methodology is known for its flexibility
According to the Waterfall model, software development is to be completed as one single project, which is then divided into different phases, with each phase appearing only once during the SDLC. However, the Agile methodology can be considered as a collection of many different projects, which are nothing but the iterations of the different phases focusing on improving the overall software quality with feedback from users or the QA team
If you want to use the Waterfall model for software development, then you have to be clear with all the development requirements beforehand as there is no scope of changing the requirements once the project development starts. The Agile methodology, on the other hand, is quite flexible, and allows for changes to be made in the project development requirements even after the initial planning has been completed
All the project development phases such as designing, development, testing, etc. are completed once in the Waterfall model while as part of the Agile methodology, they follow an iterative development approach.
As a result, planning, development, prototyping and other software development phases can appear more than once during the entire SDLC One of the major differences between Agile and Waterfall development methodology is their individual approach towards quality and testing.
In the Waterfall model, the Testing phase comes after the Build phase, but, in the Agile methodology, testing is typically performed concurrently with programming or at least in the same iteration as programming
While Waterfall methodology is an internal process and does not require the participation of customers, the Agile software development approach focuses on customer satisfaction and thus, involves the participation of customers throughout the development phase
The Waterfall model can be regarded as a stringently sequential process, however, the Agile methodology is a highly collaborative software development process, thereby leading to better team input and faster problem solving
The Waterfall model is best suited for projects which have clearly defined requirements and in which change is not expected at all, while Agile development supports a process in which the requirements are expected to change and evolve. Thus, if you are planning to develop a software that would require frequent overhauls and has to keep up with the technology landscape and customer requirements, Agile is the best approach to follow
The Waterfall model exhibits a project mindset and lays its focus strictly on the completion of project development, while Agile introduces a product mindset that focuses on ensuring that the developed product satisfies its end customers, and changes itself as the requisites of customers change
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