Selected DP-750 Microsoft Certified: Azure Databricks Data Engineer Questions Answers

A foreign catalog mirrors the external ERP database and provides read-only access through Lakehouse Federation. Consequently, it cannot host managed volumes or locally created Delta tables, and its foreign tables cannot be altered to add analytics columns. The appropriate design is to create governed views in the managed analytics catalog and have those views reference the foreign tables through fully qualified catalog.schema.table names. This preserves the ERP data in its source system, avoids duplication, and exposes standardized curated objects through Unity Catalog. Permissions can then be granted on the managed views while access to underlying foreign objects remains controlled. Unity Catalog uses a three-level namespace, and foreign catalogs are specifically intended to make external database data queryable without copying it into Databricks-managed storage. Microsoft Learn

The correct answer is C — a job cluster that uses autoscaling.

Job clusters (also called pipeline clusters in the SDP context) are created exclusively for a pipeline run and terminated when the pipeline stops. You pay only for what the pipeline uses, and there ' s no idle cost between runs. Autoscaling on a job cluster lets the pipeline expand during heavy processing and contract during lighter stages — the combination of on-demand lifecycle and elastic scaling gives the lowest operational cost.

Option A (all-purpose cluster) runs at a higher DBU rate and persists beyond the pipeline ' s lifecycle, meaning you ' re paying for it even when the pipeline isn ' t running. Option B (SQL warehouse) is optimised for interactive BI and ad-hoc queries, not for the batch/streaming workloads SDP pipelines run. Option D (single- node all-purpose) has no scaling, runs at the all-purpose DBU rate, and is capped at one node — unsuitable for any production pipeline.

The correct mapping is SCD Type 1 for equipment metadata and SCD Type 2 for IoT sensor ownership history.

SCD Type 1 overwrites the existing record whenever an attribute changes — no history is kept. Contoso ' s requirement for equipment metadata (name, manufacturer, model, commissioning date) states ' historical values are NOT required, ' which is the textbook definition of Type 1. A MERGE INTO with WHEN MATCHED THEN UPDATE handles this cleanly in Delta Lake.

SCD Type 2 creates a new row for each change, preserving the full history through effective-date or version columns. Contoso requires that ' analysts must track the full history of ownership ' as sensors change hands over time — that full audit trail is only possible with Type 2. Type 3 (keeping just the previous value in an extra column) would lose earlier ownership records, so it doesn ' t satisfy the ' full history ' requirement.

Production ingestion: Job compute

BI: Serverless SQL warehouse

Job compute is designed for automated production workloads executed through Lakeflow Jobs. Its lifecycle can be tied to the job run, providing workload isolation and avoiding the cost of maintaining an interactive all-purpose cluster continuously. It is therefore appropriate for scheduled ingestion and transformation processing. A serverless SQL warehouse is designed for BI and Databricks SQL workloads. It provides rapid startup, automatic infrastructure management, scaling, and optimized SQL-query execution for dashboards and reporting tools. All-purpose compute is intended primarily for interactive notebook development and exploration, while shared compute does not provide the same job-specific isolation or SQL-serving experience. Consequently, job compute should support production ingestion, and a serverless SQL warehouse should serve the BI workload.