Data Engineer

How can an SQL injection occur through a date input field?

SELECT * FROM table1 AS t1 LEFT JOIN table2 AS t2 ON t1.date_start > t2.date_start d = { True: 42, 1: 2, 1.0: 100500 } print(d)

SELECT * FROM table1 AS t1 LEFT JOIN table2 AS t2 ON t1.date_start > t2.date_start

SELECT * FROM table1 AS t1 LEFT JOIN table2 AS t2 ON t1.date_start > t2.date_start --DML CREATE TABLE IF NOT EXISTS Employee (id int, salary int, departmentId int); INSERT INTO Employee (id,salary,departmentId) VALUES (1, 70000, 1),(2, 94000, 1),(3, 85000, 1),(4, 80000, 2),(5, 60000, 2),(6, 62000, 3),(7, 90000, 3),(8, 94000, 3),(9, 94000, 3); with cte as( select *, rank() over(partition by departmentId order by salary desc) as max_salary from Employee ) select * from cte where max_salary = 1

What is the difference between EXPLAIN and EXPLAIN ANALYZE?

What happens when queries are parallelized in a single-node Postgres?

Have you ever had to create reports, dashboards, visualizations (BI)?

What is SQL injection?

Starting from which features can it be said that a data store is needed?.

How do you approach a situation when the business requests a report with data visualization for a new promotion?

What is VACUUM in PostgreSQL? What is it used for?

What are the disadvantages of MPP architecture in Greenplum?

What is a decorator in Python and what is it used for (in the context of Airflow)?

Name five Git commands.

What questions do you have for me?

What are the pros and cons of ACID besides read speed?

What is the purpose of a foreign key constraint and what is the meaning of delete/update restrictions when dependent records exist?

Tell me about Greenplum — data storage formats, row-based and columnar storage.

Do you know about the Avro format?

What is duck typing?