Data Engineer

Where can I view task logs in Airflow?

How does ClickHouse work and how does it differ from PostgreSQL?

How does Pandas handle missing data?

Threading, multiprocessing, asyncio: what is the difference and when is it better to use each?

Where does parallelism appear in Airflow?

How to parse large XML files in ZIP and load into ClickHouse using Python?

What is GIL (Global Interpreter Lock)?

How do generators differ from lists in Python?

How does ORDER BY affect the ClickHouse table and what keys are better to choose?

What types of indexes are available in PostgreSQL?

How to update a table in ClickHouse so that users do not notice (atomic replacement)?

How is Pandas better than regular lists and dictionaries in Python?

How does the granularity size affect the ClickHouse table?

How not to kill Jupyter or Pandas by memory?

What do Airflow task logs usually consist of?

What is an idempotent DAG/task in Airflow?

What are window functions used for?

How to create many identical tasks in Airflow in parallel (for example, to upload many identical files)?

What is the difference between WHERE and HAVING?

How does JOIN work in ClickHouse?