10+ Damco Solutions Interview Questions and Answers

Types of joins in SQL include inner join, outer join, left join, and right join.

• Inner join: returns rows when there is a match in both tables

• Outer join: returns all rows when there is a match in one of the 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

Load balancing in Kubernetes is achieved using a service called Kubernetes Service.

• Create a Kubernetes Service object with a type of 'LoadBalancer'

• The Service will automatically create an external load balancer that will distribute traffic to the pods in the service

• The load balancer will route traffic based on the service's selector

Joins are used to combine data from two or more tables in SQL.

• Joins are used to retrieve data from multiple tables based on a related column between them.

• There are different types of joins such as inner join, left join, right join, and full outer join.

• Inner join returns only the matching rows from both tables, left join returns all rows from the left table and matching rows from the right table, right join returns all rows from the right table and matching rows from the left ...read more

Delete removes rows from a table, truncate removes all rows from a table, drop removes a table from the database.

• Delete is a DML command which removes specific rows from a table.

• Truncate is a DDL command which removes all rows from a table but keeps the table structure.

• Drop is a DDL command which removes an entire table from the database.

• Delete can be rolled back, truncate cannot be rolled back, drop cannot be rolled back.

• Example: DELETE FROM table_name WHERE condition;

• Exampl...read more

SQL Developer interview question on removing duplicates, finding third highest salary, normalization, and indexes.

• To remove duplicates, use the DISTINCT keyword or GROUP BY clause

• To find third highest salary, use the LIMIT keyword with OFFSET 2

• Normalization is the process of organizing data in a database to reduce redundancy and improve data integrity

• Indexes are used to improve query performance by creating a data structure that allows for faster data retrieval

• Drawbacks of in...read more

OpenAPI specification is a standard for defining RESTful APIs.

• OpenAPI specification allows developers to describe APIs in a standardized format using YAML or JSON.

• It includes information such as endpoints, parameters, request/response formats, authentication methods, etc.

• Tools like Swagger UI can generate interactive API documentation based on OpenAPI specifications.

Rate limiting can be implemented using techniques like token bucket algorithm or sliding window algorithm.

• Implement token bucket algorithm to limit the number of requests a user can make within a certain time frame.

• Use sliding window algorithm to track the number of requests made in a specific time window and reject requests that exceed the limit.

• Consider using libraries like Guava RateLimiter in Java for easy implementation.

Structured Query Language (SQL) is a programming language used to manage and manipulate relational databases.

• SQL is used to create, modify, and delete databases, tables, and data.

• It is used to retrieve data from databases using queries.

• SQL is used to insert, update, and delete data in databases.

• It is a standard language used by most relational database management systems (RDBMS).

API versioning is a practice of managing different versions of an API to ensure compatibility and smooth transitions for users.

• Use URL paths to differentiate between different versions of the API (e.g. /v1/resource vs /v2/resource)

• Include version information in the request headers (e.g. Accept header)

• Implement versioning through query parameters (e.g. /resource?version=1)

• Use custom media types to specify API versions (e.g. application/vnd.company.resource.v1+json)

API contract defines the rules and requirements for interacting with an API.

• API contract specifies the endpoints, methods, parameters, and data formats that can be used to access the API.

• It also includes information on authentication, rate limits, error handling, and versioning.

• Developers must adhere to the API contract to ensure proper communication and functionality.

• Examples: RESTful APIs typically have a clear API contract documented in OpenAPI or Swagger.

• API contracts hel...read more

Normalization is the process of organizing data in a database to reduce redundancy and improve data integrity.

• Normalization involves breaking down data into smaller, more manageable tables

• It helps in reducing data redundancy by storing data in a structured way

• Normalization ensures data integrity by avoiding update anomalies

• There are different normal forms like 1NF, 2NF, 3NF, etc.

• Example: In a database, instead of storing customer details in multiple tables, we can normalize i...read more