30+ L&T Technology Services Interview Questions and Answers

Questions related to SQL concepts and syntax for Assistant System Analyst position.

• SQL joins - types and syntax

• Difference between joins

• View - definition and syntax

• Cursor - definition

• Trigger - definition and types

• Example of using joins

• Index - definition, creation and syntax

• Difference between drop, truncate and delete

• Function - definition and creation

Runnable is a functional interface with a run() method, while Callable is a functional interface with a call() method that can return a result or throw an exception.

• Runnable does not return a result or throw a checked exception, while Callable can return a result or throw a checked exception.

• Callable is used in scenarios where you need to return a result or handle checked exceptions, while Runnable is used for simple tasks that do not require a return value.

• Example: Runnable ...read more

Completing on time is more important than completing scope perfectly.

• Meeting deadlines is crucial for business success.

• Scope can always be adjusted or expanded later.

• Delivering on time builds trust with clients and stakeholders.

• Late delivery can result in financial losses and damage to reputation.

• Effective project management can balance scope and time constraints.

Spring auto configuration automatically configures Spring beans based on classpath and property settings.

• Spring scans classpath for certain annotations like @Component, @Service, @Repository, @Controller, etc.

• Based on these annotations and property settings, Spring automatically configures beans.

• Auto configuration can be customized using @Conditional annotations or configuration classes.

• Example: @SpringBootApplication annotation triggers auto configuration for Spring Boot app...read more

I have used annotations like @RestController, @Autowired, @RequestMapping, @Service, @Component, @Repository in Spring Boot.

• Used @RestController to define RESTful web services.

• Used @Autowired to inject dependencies.

• Used @RequestMapping to map web requests to specific handler methods.

• Used @Service to mark a class as a service component.

• Used @Component to mark a class as a Spring component.

• Used @Repository to mark a class as a data access component.

Bootstrap is a front-end framework for developing responsive and mobile-first websites. HTML is a markup language for creating web pages, while CSS is used for styling those pages.

• Bootstrap is a popular front-end framework that helps in designing responsive and mobile-first websites

• HTML is a markup language used for creating the structure of web pages

• CSS is a styling language used for designing the layout and appearance of web pages

• Example of HTML tags: <div>, <p>, <a>, <img>...read more

Transaction management in Spring helps in managing database transactions in a consistent and reliable manner.

• Spring provides support for both programmatic and declarative transaction management.

• Programmatic transaction management involves handling transactions in code using TransactionTemplate or PlatformTransactionManager.

• Declarative transaction management involves using annotations like @Transactional to define transactional behavior at the method or class level.

• Spring supp...read more

Strings are immutable in Java to ensure thread safety, security, and optimization.

• Immutable strings are thread-safe as they cannot be modified concurrently by multiple threads.

• Immutable strings enhance security by preventing malicious code from altering the string content.

• String interning is possible due to immutability, allowing for memory optimization.

• Examples: String str = "Hello"; str.concat(" World"); // This does not modify str, but creates a new string

Exception propagation in Java is the process of passing an exception from one method to another in the call stack.

• Exceptions can be thrown in a method and propagated up the call stack until they are caught and handled.

• If an exception is not caught in a method, it will be propagated to the calling method.

• This continues until the exception is caught or reaches the top of the call stack.

• Example: If a method 'A' calls method 'B' and an exception occurs in 'B', it will be propagat...read more

JDBC is a Java API for connecting and executing SQL queries on databases. The return type of a statement in JDBC is boolean.

• JDBC stands for Java Database Connectivity.

• It allows Java programs to interact with databases using SQL queries.

• The return type of a statement in JDBC is boolean, indicating whether the query was successfully executed.

The question asks about the differences between delete, truncate, and drop in SQL, as well as the syntax of DML, DCL, and TCL statements.

• DELETE is a DML statement used to remove specific rows from a table.

• TRUNCATE is a DDL statement used to remove all rows from a table.

• DROP is a DDL statement used to remove an entire table from the database.

• DML (Data Manipulation Language) statements are used to manipulate data in the database, such as INSERT, UPDATE, and DELETE.

• DCL (Data Con...read more

Windows Server 2019 has improved security features, better performance, and enhanced hybrid cloud integration compared to Windows Server 2016.

• Windows Server 2019 has improved security features such as Windows Defender Advanced Threat Protection (ATP) and Shielded Virtual Machines.

• Windows Server 2019 offers better performance with support for up to 48TB of RAM and 256 logical processors.

• Windows Server 2019 has enhanced hybrid cloud integration with Azure, including Azure Backu...read more

Patching procedure in Windows involves regularly updating the operating system with security patches and updates.

• Regularly check for updates through Windows Update

• Download and install updates as recommended

• Schedule regular maintenance windows for patching

• Test patches in a non-production environment before deploying

• Monitor system performance after patching for any issues

Second level cache in Hibernate is used to cache data at the session factory level to reduce database hits.

• Second level cache stores objects across sessions to reduce database calls

• Improves performance by reducing database hits

• Configurable cache providers like Ehcache, Infinispan can be used

JDBC is a Java API for connecting and executing queries on a database. Hibernate is an ORM framework that simplifies database interactions.

• JDBC is a low-level API for database connectivity in Java, requiring manual handling of SQL queries and connections.

• Hibernate is a high-level ORM framework that maps Java objects to database tables, abstracting away the need for manual SQL queries.

• JDBC is more suitable for simple database operations, while Hibernate is preferred for comple...read more

Optimizing queries involves using indexes, limiting result sets, avoiding unnecessary joins, and optimizing database schema.

• Use indexes on columns frequently used in WHERE clauses

• Limit result sets by using pagination or filtering

• Avoid unnecessary joins by denormalizing data or using subqueries

• Optimize database schema by reducing redundancy and normalizing data

Thread safety ensures that shared data is accessed and modified by multiple threads in a safe and consistent manner.

• Thread safety is important in multi-threaded programming to prevent race conditions and ensure data integrity.

• It can be achieved through synchronization mechanisms like locks, mutexes, and atomic operations.

• For example, using synchronized keyword in Java to protect critical sections of code from concurrent access.

I know several common Linux commands used for system administration and troubleshooting.

• ls - list directory contents

• cd - change directory

• pwd - print working directory

• cp - copy files and directories

• mv - move/rename files and directories

• rm - remove/delete files and directories

• grep - search for patterns in files

• chmod - change file permissions

• sudo - execute a command as a superuser

• top - display and update sorted information about processes

• df - report file system disk space usage

GPT allows for more partitions and larger disk sizes compared to MBR.

• GPT supports up to 128 partitions while MBR supports only 4 primary partitions.

• GPT can handle disk sizes larger than 2TB, while MBR is limited to 2TB.

• GPT stores partitioning and boot data in multiple locations for redundancy, while MBR stores this information in a single location.

• GPT uses GUID (Globally Unique Identifier) to identify partitions, while MBR uses partition table entries.

The @Qualifier annotation is used in Spring to specify which bean should be autowired when multiple beans of the same type are present.

• Used to disambiguate beans of the same type

• Helps in selecting a specific bean when multiple beans of the same type are available

• Can be used in conjunction with @Autowired annotation

The return type of the add method depends on the specific implementation and requirements of the program.

• Return type can be int, double, void, or any other data type depending on what the method is supposed to do.

• For example, an add method for adding two integers may have a return type of int.

• If the add method is simply updating a value and not returning anything, the return type may be void.

Port number for SMTP is 25

• Port number for SMTP is 25

• SMTP stands for Simple Mail Transfer Protocol

• SMTP is used for sending emails

Arrays are a data structure that stores a collection of elements of the same data type in a contiguous memory location.

• Arrays have a fixed size determined at the time of declaration.

• Elements in an array are accessed using an index starting from 0.

• Example: String[] names = new String[5];

SQL joins are used to combine rows from two or more tables based on a related column between them.

• Inner Join: Returns rows when there is at least one match in both tables

• Left Join: Returns all rows from the left table and the matched rows from the right table

• Right Join: Returns all rows from the right table and the matched rows from the left table

• Full Outer Join: Returns rows when there is a match in one of the tables

Data structures in Java are used to store and organize data efficiently.

• Java provides built-in data structures like arrays, lists, sets, maps, queues, and stacks.

• Arrays are used to store a fixed-size collection of elements of the same data type.

• Lists like ArrayList and LinkedList can dynamically grow and shrink in size.

• Sets ensure unique elements and maps store key-value pairs.

• Queues follow the FIFO (First In First Out) principle, while stacks follow the LIFO (Last In First O...read more

DDL stands for Data Definition Language and DML stands for Data Manipulation Language. JDK is Java Development Kit, JRE is Java Runtime Environment, and a constructor is a special type of method in Java.

• DDL is used to define the structure of database objects like tables, indexes, etc. Examples include CREATE TABLE, ALTER TABLE, DROP TABLE.

• DML is used to manipulate data in the database. Examples include INSERT, UPDATE, DELETE.

• JDK is a software development kit used for developi...read more

Application and production support involves maintaining and troubleshooting software applications in a live environment.

• Responsible for resolving technical issues and bugs in applications

• Provide assistance to end users in using the applications

• Monitor application performance and ensure availability

• Implement changes and updates to applications as needed

• Collaborate with development teams to address issues and improve functionality

vSphere is a virtualization platform by VMware for managing virtualized infrastructure.

• Virtualization platform by VMware

• Allows for managing virtualized infrastructure

• Includes features like VM management, resource allocation, and monitoring

Linux command is used to interact with the Linux operating system through the command line interface.

• ls - list directory contents

• cd - change directory

• pwd - print working directory

• mkdir - make a new directory

• rm - remove files or directories

SQL join is used to combine rows from two or more tables based on a related column between them.

• SQL join is used to retrieve data from multiple tables based on a related column.

• Types of SQL joins include INNER JOIN, LEFT JOIN, RIGHT JOIN, and FULL JOIN.

• INNER JOIN returns rows when there is at least one match in both tables.

• LEFT JOIN returns all rows from the left table and the matched rows from the right table.

• RIGHT JOIN returns all rows from the right table and the matched r...read more

Spring Boot simplifies the development of Java applications by providing a set of tools and conventions for building production-ready applications quickly.

• Provides a pre-configured environment for developing and deploying Java applications

• Reduces the need for boilerplate code and configuration

• Supports embedded servers for easy deployment

• Offers built-in support for monitoring, metrics, and health checks

• Integrates seamlessly with other Spring projects like Spring Data, Spring S...read more