The Databricks Certified Data Analyst Associate Exam (Databricks-Certified-Data-Analyst-Associate)

Databricks SQL uses SQL warehouses as its compute resource. A SQL warehouse is a dedicated compute engine designed specifically for executing SQL queries and powering dashboards within the Databricks workspace. According to Databricks official documentation, SQL warehouses are optimized for fast, scalable query execution, whereas clusters are used primarily for data engineering and machine learning workloads.

Option A is correct. Classic enterprise data warehouses commonly use proprietary storage formats, while the Databricks lakehouse is built around open table formats such as Delta Lake and Iceberg. Databricks documentation states that Delta Lake is open source and that the Databricks platform uses no proprietary data formats to avoid vendor lock-in. Schema enforcement and ACID transactions are important Delta Lake capabilities, but they are not the best differentiator “over classic enterprise data warehouse solutions,” because enterprise warehouses also typically provide managed reliability and transactional behavior. The unique lakehouse advantage here is open-source/open-format interoperability. References: Databricks Delta Lake and lakehouse architecture documentation.

 An external table is a table that is defined in the metastore, but its data is stored outside of the Databricks environment, such as in S3, ADLS, or GCS. When an external table is dropped, only the metadata is deleted from the metastore, but the data files are not affected. This is different from a managed table, which is a table whose data is stored in the Databricks environment, and whose data files are deleted when the table is dropped. To delete the data files of an external table, the analyst needs to specify the PURGE option in the DROP TABLE command, or manually delete the files from the storage system. References: DROP TABLE, Drop Delta table features, Best practices for dropping a managed Delta Lake table

 The SQL code provided in Option D is the correct way to create a view named sales_by_employee that will always stay up-to-date with the sales and employees tables. The code uses the CREATE OR REPLACE VIEW statement to define a new view that joins the sales and employees tables on the employee_id column. It selects the employee_name as sales_person and all sales for each employee, ensuring that the data entity/object is always up-to-date when new data are added to these tables.

The answer can be verified from Databricks SQL documentation which provides insights on creating views using SQL queries, joining tables, and selecting specific columns to be included in the view. Reference link: Databricks SQL

 Option A uses the SELECT DISTINCT statement to remove duplicate rows from the table_bronze and create a new table table_silver with the deduplicated data. This is the correct way to deduplicate data using Spark SQL12. Option B simply inserts all the rows from table_bronze into table_silver, without removing any duplicates. Option C is not a valid syntax for Spark SQL, as there is no MERGE DEDUPLICATE statement. Option D appends all the rows from table_bronze into table_silver, without removing any duplicates. Option E overwrites the existing data in table_silver with the data from table_bronze, without removing any duplicates. References: Delete Duplicate using SPARK SQL, Spark SQL - How to Remove Duplicate Rows

 A Delta Lake-based data lakehouse is a data platform architecture that combines the scalability and flexibility of a data lake with the reliability and performance of a data warehouse. One of the key advantages of using a Delta Lake-based data lakehouse over common data lake solutions is that it supports ACID transactions, which ensure data integrity and consistency. ACID transactions enable concurrent reads and writes, schema enforcement and evolution, data versioning and rollback, and data quality checks. These features are not available in traditional data lakes, which rely on file-based storage systems that do not support transactions. References:

Delta Lake: Lakehouse, warehouse, advantages | Definition

Synapse – Data Lake vs. Delta Lake vs. Data Lakehouse

Data Lake vs. Delta Lake - A Detailed Comparison

Building a Data Lakehouse with Delta Lake Architecture: A Comprehensive Guide

Option D is correct because the table has zero real null values, but the result contains null values representing subtotal and grand-total rows. That behavior is produced by WITH CUBE, which creates aggregations for combinations of grouping columns, including (group_1, group_2), (group_1), (group_2), and the grand total (). The Databricks SQL documentation states that GROUP BY supports advanced aggregations through CUBE, and that CUBE is shorthand for grouping sets. Option A only returns detailed groups. Options B and C use invalid syntax in Databricks SQL. Reference: Databricks GROUP BY clause documentation.

The correct answer is C because the issue is a resource constraint failure, and the analyst needs to identify which operator is consuming excessive memory. In Query Profile, Memory peak shows memory usage at the operator level and helps identify the operator causing resource overuse. Time spent helps identify slow operators, shuffle read size helps analyze data movement, and bytes spilled to disk indicates spill behavior, but the most direct metric for resource overuse due to memory pressure is memory peak.

Official documentation extract used: Databricks Query Profile graph view shows metrics such as “Time spent, Memory peak, and Rows.”

Option A is correct. The user is not a member of the auditing group, so is_member( " auditing " ) evaluates to false and the ELSE age > = 18 branch controls the filter. Rows with age > = 18 are returned; rows under 18 are omitted. “Age greater than 17” is equivalent to age > = 18 for integer ages. Official Databricks extract: is_member() “returns TRUE if the current user is a member” of the specified group, and Databricks describes dynamic views as views that can filter rows based on group membership.