LFC Databricks SQL & Warehousing 3

Question 1

Which Databricks SQL function returns the current timestamp in the session's local timezone?

Accepted Answer

Both NOW() and CURRENT_TIMESTAMP()

Answer

In Databricks SQL both NOW() and CURRENT_TIMESTAMP() return the current timestamp with the session timezone applied.

Question 2

A data engineer wants to read only the new rows added to a Delta table since the last pipeline run. Which Databricks SQL / Delta Lake feature best supports this pattern?

Accepted Answer

CHANGE DATA FEED (CDF) with table_changes()

Answer

Change Data Feed exposes a table_changes() function that returns only inserted, updated, or deleted rows since a given version or timestamp.

Question 3

In Databricks SQL, what does the QUALIFY clause do?

Accepted Answer

Filters rows based on a condition applied after window functions are evaluated

Answer

QUALIFY filters the result set of window functions similarly to how HAVING filters aggregations, without needing a subquery.

Question 4

A SQL Warehouse is configured with min clusters = 1 and max clusters = 5. Under what condition will the warehouse scale UP to additional clusters?

Accepted Answer

When the query queue length reaches a platform-defined threshold

Answer

Databricks auto-scales SQL Warehouses by adding clusters when the query queue grows beyond an internal threshold, not based on CPU.

Question 5

Which statement correctly describes a Databricks SQL Dashboard compared to a Notebook?

Accepted Answer

Dashboards are read-only presentations of visualizations; notebooks allow code execution

Answer

Databricks SQL Dashboards are designed as read-only visual presentations of query results, while notebooks are interactive coding environments.

(LFC) Lakehouse Fundamentals Certification Practice Test

(LFC) Lakehouse Fundamentals Certification Practice Test

LFC Databricks SQL & Warehousing 3