Technology Questions

There are many algorithms that can be used to analyze the database to check the maintenance of all the data sets that are already present. The different types of cluster models include as follows:

- Connectivity models: these are the models that connect one cluster to another cluster. This includes the example of hierarchical clustering that is based on the distance connectivity of one model to another model. 

- Centroid models: these are the models that are used to find the clusters using the single mean vector. It includes the example of k-means algorithm.

- Distribution models: it includes the specification of the models that are statistically distributed for example multivariate normal distribution model.

- Density models: deals with the clusters that are densely connected with one another in the regions having the data space. 

- Group models: specifies the model that doesn’t provide the refined model for the output and just gives the grouping information

1) List down usecases (taken from business cases) from function specs. For each use case write a test case and categorize them into sanity tests, functionality, GUI, performance etc. Then for each test case, write its workflow. 

2) For a GUI application - make a list of all GUI controls. For each control start writing test cases for testing of the control UI, functionality (impact on the whole application), negative testing (for incorrect inputs), performance etc.  

- Web browser functions are to provide the resources or information to the user when asked by them. 

- It processes the user inputs in the form of URL like https://www.google.com in the browser and allows the access to that page. 

- URL is used to identify the resources and fetch them from the server and displays it to the client. 

- It allows the user to interact with the web pages and dynamic content like surveys, forms, etc. 

- It also allows the user to navigate through the complete web page and see its source code in the HTML format. 

- It provides security to the data and the resources that are available on the web that is by using the secure methods.

Data warehousing is a process of repository of electronic data of an organization. For the purpose of reporting and analysis, data warehousing is used. The essence concept of data warehousing is to provide data flow of architectural model from operational system to decision support environments. 

Star schema: A highly de-normalized technique. A star schema has one fact table and is associated with numerous dimensions table and depicts a star.

Snow flake schema: The normalized principles applied star schema is known as Snow flake schema. Every dimension table is associated with sub dimension table.

Differences:

- A dimension table will not have parent table in star schema, whereas snow flake schemas have one or more parent tables.

- The dimensional table itself consists of hierarchies of dimensions in star schema, where as hierarchies are split into different tables in snow flake schema. The drilling down data from top most hierarchies to the lowermost hierarchies can be done.

Windows services, previously known as NT services, are applications that are installed on the system as system services. In other words, Windows services are applications that run in the background with the Windows operating system. The primary use of Windows services is to reduce the consumption of memory required for performing backend operations. Let's take an example to understand this easily. Suppose you want to perform a variety of functions, such as monitor the performance of your computer or application, check the status of an application, and manage various devices, such as printers.

In such a case, you can use Windows services to reduce memory consumption. In addition, Windows services can run on your system even if you have not logged on to your computer. In addition, these services do not have any user interface.

Oracle Real Application Clusters (RAC) is a software component we can add to a high-availability solution that enables users on multiple machines to access a single database with increased performance. RAC comprises two or more Oracle database instances running on two or more clustered machines and accessing a shared storage device via cluster technology. To support this architecture, the machines that host the database instances are linked by a high-speed interconnect to form the cluster. Oracle RAC offers features in the following areas:

- Scalability

- Availability

- Load balancing

- Failover

Node.js uses a single threaded model with event looping.