Java

What are the advantages and disadvantages of using indexes for individual columns in a database?

Junior — Middle

Т-Банк

Have you used the SELECT statement in data update operations (UPDATE)?

Junior — Middle

Т-Банк

Can you explain the concept of Stream API in Java and how it is used for data processing?

Junior — Middle

ТОП КЕЙССБЕРБАРС групп+4

What types of indexes exist in SQL database management systems?

Junior — Middle

EAGARAstonТ-Банк+1

What can lead to a decrease in function execution performance?

Junior — Middle

Т-Банк

Can cyclic dependencies lead to memory leaks in a program?

Junior — Middle

Т-Банк

What steps will you take to identify the causes of regular service restarts related to the OutOfMemoryError error?

Junior — Middle

Т-Банк

Read the code and highlight errors. /** * A client with a purchased ticket can choose a specific seat for an additional fee. * The base price of seats is determined by tariffs (external service). * For clients with certain tariffs (PREMIUM, ULTRA), a discount is applied at payment. * When booking, an invoice is issued to the client for payment. Payment management is handled by a third-party service. */ @Service public class SeatBookingService { @Autowired private SeatBookingRepository seatBookingRepository; @Autowired private TicketRepository ticketRepository; @Autowired private TariffClient tariffClient; @Autowired private CustomerClient customerClient; @Autowired private PaymentClient paymentClient; /** * Booking. * @param seatCode seat code (e.g., 19A) * @param ticketId ticket ID */ @Transactional public void bookSeat(String seatCode, UUID ticketId) { var ticket = ticketRepository.findById(ticketId); //book var seatBooking = new SeatBooking(seatCode, ticket.get().getFlightId(), ticketId, BookingStatus.BOOKED); seatBookingRepository.save(seatBooking); //find base tariff for the selected seat on the plane var basePrice = tariffClient.getBasePrice(ticket.get().getPlaneModel(), seatCode); //find customer data Long userId = (Long) SecurityContextHolder.getContext().getAuthentication().getPrincipal(); var userData = customerClient.getCustomer(userId); System.out.println("User found " + userData.getFio() + " document number " + userData.getDocument()); var price = basePrice; if (userData.getTariff() == "PREMIUM") { //50% discount price = basePrice * 0.5d; } if (userData.getTariff() == "ULTRA") { //20% discount price = basePrice * 0.8d; } var invoice = new Invoice(price, ticketId, userId); //issue invoice paymentClient.sendInvoice(invoice); System.out.println("Invoice issued"); } @Data @Table("seat_booking") public class SeatBooking { @Column private String seatCode; @Column private UUID flightId; @Column private UUID ticketId; @Column private BookingStatus status; } public enum BookingStatus { BOOKED, PAID; }

Senior

Т-Банк

Have you had experience interacting with data or resource providers?

Junior — Middle

Т-Банк

Can you explain what is meant by an atomic data type?

Junior — Middle

Акселератор возможностейИннотехАльфа-Банк+2

The mechanism of the SELECT FOR UPDATE operator in databases and its role in managing concurrent access.

Junior — Middle

Т-Банк

Why does a ConcurrentModificationException occur when modifying an ArrayList simultaneously during iteration?

Junior — Middle

Т-Банк

What actions will you take if the delays in database query execution become significant under increased system load?

Middle

Т-Банк

What methods can be used to increase the speed of table search?

Junior — Middle

Т-Банк

Can you list the main methods provided by the Stream API in Java?

Junior — Middle

айтекоБАРС группООО Динамика+11

Can you explain how the exception inheritance structure is organized in a programming language?

Junior — Middle

СБЕРТ-Банк

Is the related record automatically deleted from the child table when the related key is deleted from the parent table?

Junior — Middle

Т-Банк

What distinguishes an optimistic approach to locking from a pessimistic one in the context of concurrency control in databases?

Junior — Middle

IT OneТ-Банк

What ways can you improve the speed of executing this method?

Junior — Middle

Т-Банк

Explain the concept of type erasure and its main purpose in programming.

Junior — Middle

Т-Банк