Amazon Business Intelligence Engineer interview questions

> Interview loop: 1 -> Interview with Business Intelligence Engineer - Technical Interview: They performed some questions in detail for Dive Deep leadership principle (they wanted to know everything: how did I processed data, table names, column names, methods used) The engineer did a question on how to load a CSV file with python, and also made me resolve two SQL exercises (SELECT-JOIN type queries). Lastly asked if I had some experience on reporting software (Power BI, Tableu, QuickSight) and how did I rate myself, and the same question but for python. 2 -> Interview with Hiring manager The manager explained me the business, they then went to perform some leadership questions base on leadership principles (Ownership was one, and I think the other one was Are Right, A lot). 3 -> Interview with Bar raiser Bar raiser performed some questions based on leadership principles, nothing technical. I think one was Learn and Be Curious and the other one was one between the following principles: Bias for Action, Have Backbone; Disagree and Commit and Owernship. 4 -> Interview with team member (QA Manager) Leardership questions based on Invent and Simplify and I think the other one was Ownership.

What is a primary key?