Headstream Technologies Senior Software Engineer Interview Questions, Process, and Tips

Garbage collection is an automatic memory management process that frees up memory occupied by objects that are no longer in use.

• Garbage collection is a process of identifying and freeing up memory that is no longer in use by the program.

• It is done automatically by the programming language runtime environment.

• Garbage collection helps prevent memory leaks and improves program performance.

• Examples of programming languages...read more

SOLID is a set of principles for object-oriented programming to make software more maintainable, scalable, and robust.

• S - Single Responsibility Principle: A class should have only one reason to change.

• O - Open-Closed Principle: A class should be open for extension but closed for modification.

• L - Liskov Substitution Principle: Subtypes should be substitutable for their base types.

• I - Interface Segregation Principle: A c...read more

CLR stands for Common Language Runtime. It is a component of .NET framework that manages execution of .NET programs.

• CLR is responsible for memory management, security, and exception handling.

• It compiles the intermediate language code into machine code.

• CLR provides a common type system and runtime environment for all .NET languages.

• It allows for cross-language integration and interoperability.

• Examples of languages that

Abstract classes provide a blueprint for other classes to follow and cannot be instantiated.

• Abstract classes are used when we want to provide a common interface for a group of related classes.

• They cannot be instantiated and must be extended by a subclass.

• Abstract methods are declared in the abstract class and implemented in the subclass.

• They can have both abstract and non-abstract methods.

• Example: Animal is an abstract...read more

Association, Composition and Aggregation are three types of relationships between classes in object-oriented programming.

• Association is a relationship between two classes where one class uses the other class as a parameter or return type.

• Composition is a relationship between two classes where one class owns the other class and is responsible for its creation and destruction.

• Aggregation is a relationship between two cla...read more

Identifying slow running query in a 1000 line stored procedure

• Use SQL Server Profiler to trace the stored procedure and identify the slow running query

• Check the execution plan of the stored procedure to identify the slow running query

• Use SET STATISTICS TIME ON to measure the execution time of each query in the stored procedure

• Divide the stored procedure into smaller parts and test each part to identify the slow running

Clustered index is only one for a table to ensure efficient data retrieval and storage.

• Clustered index determines the physical order of data in a table.

• Only one clustered index can be created per table.

• It is recommended to choose a column with unique and sequential values as the clustered index.

• Clustered index is used for range searches and sorting.

• Non-clustered indexes can be created for additional search paths.

Temporary table is a table that exists temporarily in the database and is used to store intermediate results.

• Temporary tables are created and used within a single session or transaction.

• They are stored in the tempdb database in SQL Server.

• They can be used to store intermediate results during complex queries or to simplify complex joins.

• They are automatically dropped when the session or transaction ends or when they are...read more

SQL covered index is an index that contains all the columns needed for a query, reducing the need for table lookups.

• A covered index can improve query performance by reducing the number of disk I/O operations.

• It is created by including all the columns needed for a query in the index.

• Covered indexes are particularly useful for queries that involve large tables or complex joins.

• Example: CREATE INDEX idx_name ON table_name

Table variable is a variable that holds a table-like structure in memory for temporary use.

• Table variables are declared using the DECLARE keyword in SQL Server.

• They can be used to store temporary data within a stored procedure or a batch of SQL statements.

• Table variables have a scope limited to the batch or stored procedure in which they are declared.

• They are automatically dropped when the batch or stored procedure com...read more

Optimizing query to fetch records from employee table based on city

• Create an index on the City column

• Use a WHERE clause with an index hint

• Use a stored procedure to cache the query results

• Use a materialized view to precompute the query results

MSDB is a system database in SQL Server used for managing SQL Server Agent jobs, alerts, and operators.

• MSDB stands for Microsoft SQL Server Database

• It stores metadata and configuration information for SQL Server Agent

• It contains tables for job scheduling, alerts, and operators

• It also stores backup and restore history information

SQL NOLOCK is a query hint used to allow a SELECT statement to read data from a table without acquiring a shared lock.

• NOLOCK is used to improve query performance by allowing dirty reads

• It is not recommended to use NOLOCK in production environments

• Other query hints include UPDLOCK, ROWLOCK, and XLOCK

Async and Await are keywords used in asynchronous programming in JavaScript.

• Async and Await are used to handle asynchronous operations in JavaScript.

• Async is used to define a function that returns a promise.

• Await is used to wait for the promise to resolve before continuing the execution.

• Async and Await make asynchronous code look like synchronous code.

• Async and Await are supported in modern browsers and Node.js.

Collections are generic classes to store and manipulate groups of objects. Dictionary is a collection of key-value pairs. KeyValuePair is a struct that represents a key-value pair.

• Collections are used to store and manipulate groups of objects.

• Dictionary is a collection of key-value pairs where each key is unique.

• KeyValuePair is a struct that represents a key-value pair and is used in Dictionary.

• Collections and Dictiona...read more

Yes, SQL Functions can be used on the JOIN Clause.

• SQL Functions can be used on the JOIN Clause to manipulate the data before joining.

• Examples of SQL Functions that can be used on the JOIN Clause are CONCAT, SUBSTRING, and DATE_FORMAT.

• Using SQL Functions on the JOIN Clause can improve query performance and reduce the amount of data transferred.

SQL functions return a single value of a specified data type.

• SQL functions can return various data types such as integer, string, date, etc.

• The return type of a function is specified in the function declaration.

• Functions can be used in SELECT, WHERE, and other SQL statements to manipulate data.

• Examples of SQL functions include COUNT, AVG, MAX, MIN, and CONCAT.

• Functions can also be user-defined using the CREATE FUNCTION

MVC Data Annotations are attributes used to define validation rules and metadata for model properties in ASP.NET MVC applications.

• Used to validate user input on the server-side

• Can be used to specify display names, format strings, and more

• Examples include [Required], [StringLength], and [RegularExpression]

Partial views are reusable components of a view that can be rendered within other views.

• Partial views are used to break down complex views into smaller, more manageable pieces.

• They can be used to display common elements across multiple views, such as headers or footers.

• Partial views can be rendered within other views using the @Html.Partial() method in ASP.NET MVC.

• They can also be passed data from the parent view using...read more

Data can be transferred between controllers using various methods such as delegation, notifications, or segues.

• Delegation pattern can be used to transfer data between controllers

• Notifications can be used to broadcast data to multiple controllers

• Segues can be used to pass data between controllers during a transition

• Data can also be stored in a shared data model or database for access by multiple controllers