DBA / Database

How to protect the target table from duplicates when inserting data from a temporary table? How to update existing records with more recent data (upsert)?

How to configure indexes in PostgreSQL to ensure fast search across all keys in a table?

What types of backup do you know in MS SQL Server? Tell me about full, incremental, and log backup.

If a query has many conditions (for example, 10 columns in WHERE and JOIN) — what index would you create to improve performance?

How to set up an emergency recovery plan and failover for PostgreSQL in AWS?

When monitoring performance, what else did you pay attention to besides slow queries? (CPU, I/O operations)

What do you look at first when it comes to query planning? What bottlenecks can you see?

What is the difference between a function and a procedure?

Have you worked with Percona? Tell us about orchestration in Patroni.

How to implement an exception block in PL/SQL? How to create a user-defined exception?

Tell about your resume and professional experience.

Task 3: Find duplicate tasks (by departure_station, arrival_station, departure_date, crawler_id) and propose a plan for safe removal from the harvester_tasks_queue table.

What other types of indexes do you know?

Can you give an example of when recursive CTEs are used?

You mentioned bulk operations. Tell me more about the BULK COLLECT and FORALL combination.

How do you verify the results of a stored procedure or query? Methods and approaches.

What is AlwaysOn Availability Groups and what is this technology used for?

Middle+

Иннотех

What are LAG and LEAD?

Задание 2: Найти маршруты с активными задачами (status = 'Ready to start'), но без обновлений 30+ дней. Схемы: harvester_tasks_queue и station__crawler_mapping_with_crawler_ids.

What user authentication methods do you know in PostgreSQL?