Java

Why might a scheduler ignore an index even if it exists?

What types of relationships between tables exist in relational databases?

Senior

МТС

What design patterns have you applied in real business tasks?

How many times will a stream pass through the original collection with two maps and one collect?

What are indexes in SQL and what are they used for? What are the disadvantages?

[name] asked: How to automate the deletion of data older than 3 months?

public interface Node { Node left(); Node right(); String value(); } /* A B. C BAC A B. C D. E DBAEC */ public class TreeWalker { public String walk(Node node) { } }

Tell about one of your recent technically complex tasks — what it was and how you solved it.

How is HashMap structured internally and how does it work?

How to view SQL queries sent by JPA/Hibernate to the database?

Middle+

Т-Банк

REST HTTP methods: what are they, what is each used for, which are idempotent, which are not?

What are the advantages and disadvantages of TimescaleDB compared to Postgres?

What conclusion did you make from the situation with duplicate accruals?

Senior

ОТП Банк

Have you ever had to deal with OOM (OutOfMemoryError)? How did you debug memory issues?

Tell us about the N+1 problem in Hibernate and ways to solve it.

What indexes do you use in relational databases (PostgreSQL)? How does B-Tree differ from Hash index?

[name] asked: What is OutOfMemoryError, when does it occur, have you encountered it in practice?

What approaches to inheritance in object mapping in Hibernate are you familiar with?

Junior — Middle

Aston

Experience with gRPC and REST?

What types of locks exist at the database level?