Have you written ingestion processes for OpenMetadata that scan sources?
Middle+
175
Data Engineer
671
0
What visualization tools have you worked with and how closely have you worked with Power BI?
Senior
175
Have you ever worked with the AQE (Adaptive Query Execution) optimizer in Spark? Do you know how it works?
Middle+
174
In PostgreSQL, the row version header includes the xmax parameter. What is its role in transaction management? - To create a unique identifier for the row in the table - To check the visibility of the row to other transactions - To indicate the transaction number that deleted or updated the row - To lock the row from concurrent modifications by multiple transactions - To specify the maximum value that can be stored in a numeric column
Junior
174
For what tasks is ClickHouse poorly suited, and what would you choose instead of it?
Middle
174
Analyze gym attendance You work as an analyst in a chain of gyms. You have information about user visits and subscriptions they purchase. You need to analyze the effectiveness of subscription usage. Calculate for each subscription type: • the total number of users who used this type of subscription. Count only unique user_id; • the total number of visits for this subscription. Count all visits of users with this subscription; • the share of users of this subscription in percentage of the total number of all users (rounded to one decimal place). To calculate the share, use the ratio of the number of users with this subscription to the total number of unique users. Each user can have only one subscription. Sort the result by subscription type in alphabetical order. Input format Memberships table: • membership_id (int) — unique subscription identifier • user_id (int) — unique user identifier • membership_type (text) — subscription type Visits table:
Junior
174
How does hash join work for tables with 1,000 and 1,000,000 rows?
Senior
173
Is Greenplum an OLTP or analytical storage?
Middle
173
Why did you decide to move ranking to a separate CTE? Why couldn't it be used directly in the first CTE?
173
How to output the last full name for each client if only start_date is known (end_date is unknown)?
Middle
173
Tell us about the most significant project or task in Python over the past year.
Senior
173
Have you ever worked with query optimization? Where does optimization generally start?
Middle
173
How does your experience match the responsibilities in the vacancy: supporting and analyzing loading processes, monitoring and identifying anomalies, testing and deploying improvements in production, second-line support, checking technical documentation?
Middle
173
What is dynamic typing?
Middle
172
What was the purpose of Data Vault for you in general?
Middle
171
What is the ideal ratio between business tasks and infrastructure tasks for you?
Senior
171
What happens when data quality constraints are triggered: alert, crash, restart?
Middle+
171
Which version of Airflow have you worked with?
Middle
171
Как работать с партициями через coalesce и repartition?
Senior
171
Чем отличается EXPLAIN ANALYZE от обычного EXPLAIN? Почему его нежелательно запускать на DELETE/UPDATE запросах?
Middle
171