United Online Interview Questions and Answers

Different types of joins are Inner Join, Left Join, Right Join, and Full Outer Join.

• Inner Join returns only the matching rows from both tables

• Left Join returns all the rows from the left table and matching rows from the right table

• Right Join returns all the rows from the right table and matching rows from the left table

• Full Outer Join returns all the rows from both tables, with NULL values in the columns where there is

ACID properties ensure database transactions are reliable and consistent.

• ACID stands for Atomicity, Consistency, Isolation, and Durability.

• Atomicity ensures that a transaction is treated as a single, indivisible unit of work.

• Consistency ensures that a transaction brings the database from one valid state to another.

• Isolation ensures that concurrent transactions do not interfere with each other.

• Durability ensures that on...read more

A process is a program in execution. It is executed in OS by allocating resources and managing its execution.

• A process is a unit of work that can be scheduled and executed by the OS

• It is created by a parent process and has its own memory space and resources

• The OS manages the execution of processes by allocating resources such as CPU time and memory

• Processes can communicate with each other through inter-process communic...read more

Preventing deadlock by implementing a resource allocation strategy

• Implement a resource allocation strategy to ensure resources are not locked by multiple processes

• Use timeouts to prevent processes from waiting indefinitely for resources

• Implement a process termination strategy to release resources held by terminated processes

• Use a deadlock detection algorithm to identify and resolve deadlocks

• Ensure that processes reques...read more

strcpy function copies a string from source to destination

• The function is defined in string.h header file

• The syntax of the function is: char *strcpy(char *destination, const char *source)

• The function returns the pointer to the destination string

• The function copies the null character also from source to destination

• The destination string must have enough space to hold the source string

A database of project information.

• Includes project name, description, start and end dates, budget, and team members.

• Can be used to track progress, allocate resources, and analyze performance.

• May also include project milestones, risks, and issues.

• Examples: Trello, Asana, Jira, Microsoft Project.