Microsoft DP-750 Practice Exam Questions & Answers

Lakeflow Jobs provides native orchestration for multi-task Databricks workflows. Separate ingestion, cleansing, and curation tasks can be connected through explicit dependencies, ensuring that each stage starts only after its required upstream work succeeds. Each task can also have independent retry, notification, timeout, and compute settings, directly addressing the pipeline's resiliency requirements. Azure Data Factory could orchestrate notebooks, but it introduces another service when Lakeflow Jobs already provides the required functionality. A single notebook makes failures harder to isolate and can force successful stages to be rerun. Independently scheduled jobs rely on timing assumptions rather than actual task completion and can fail when an upstream stage runs longer than expected. Explicit Lakeflow Jobs dependencies provide reliable execution order and centralized monitoring. Microsoft Learn

COPY INTO provides a concise SQL-based mechanism for loading files from cloud storage directly into a Delta table. It requires substantially less custom code than constructing a Spark ingestion application and is suitable for a straightforward bulk load of multiple CSV files. COPY INTO is also retryable and idempotent: it tracks files already loaded into the target table and skips them during later executions, helping prevent accidental duplication. Auto Loader is optimized primarily for incremental and continuously arriving files and normally requires a streaming or triggered pipeline. Apache Spark read APIs require additional code for reading, transforming, tracking, and writing the files. Manually uploading 500 GB would be inefficient and operationally unsuitable. Therefore, COPY INTO best satisfies both implementation-speed and minimal-code requirements. Microsoft Learn

The correct answer is C --- @dlt.expect_or_fail.

Lakeflow Spark Declarative Pipelines (SDP) offers three expectation decorators, each with a different violation response:

@dlt.expect --- logs the violation as a metric but writes all records, including bad ones, to the table. Suitable for monitoring only.

@dlt.expect_or_drop --- drops violating records and continues the pipeline. The table receives only clean rows, but the pipeline update commits successfully.

@dlt.expect_or_fail --- fails the entire pipeline update when a violation is detected. The table update is never committed. This is the correct choice when data integrity is non-negotiable: 'Prevent an update to Table1 from being committed when data that violates rule1 is detected.'

@dlt.expect_all_or_drop takes a dictionary of rules and drops violating rows but still commits --- it doesn't halt the pipeline.

The correct answer is A --- Yes.

df.dropna(subset=['order_amount']) is the idiomatic PySpark way to remove rows where a specific column contains a null. It inspects only the columns listed in subset and drops any row where those columns are null. The resulting DataFrame contains only rows where order_amount is not null --- exactly what the requirement asks for.

The subset parameter is important: without it, dropna() would drop rows where ANY column is null, which could incorrectly exclude rows that have nulls in other columns but a valid order_amount. By specifying subset=['order_amount'], the filter is applied precisely and only to the column in question.

This method is semantically equivalent to df.filter(df.order_amount.isNotNull()) and to the SQL clause WHERE order_amount IS NOT NULL. Both are correct --- dropna with a subset is arguably the more readable Pythonic approach.

An Azure Storage account provides durable, comparatively low-cost retention for diagnostic and audit logs that are accessed infrequently. A lifecycle or retention policy can preserve the logs for 90 days and then remove them automatically. This matches an investigation-only access pattern without paying the ingestion and indexing charges associated with Log Analytics. Azure Monitor metrics stores numerical monitoring measurements, not the complete audit-event records required here. Azure Event Hubs is a streaming transport intended to forward events to consumers and is not the final long-term retention destination. Log Analytics is appropriate when teams need frequent querying, dashboards, and alerting, but those capabilities introduce unnecessary cost for logs reviewed only during occasional investigations. Storage therefore best satisfies centralized retention and cost requirements.

Schema evolution allows the target Delta table to incorporate compatible new source columns instead of failing when the incoming schema changes. This is the appropriate response to additive schema drift and avoids manually rebuilding tables whenever the source evolves. Creating a separate table for every schema version would fragment the dataset and increase operational effort. Disabling schema enforcement removes valuable protection against incompatible or corrupt data rather than handling legitimate evolution safely. Row filters operate on records and cannot remove an unexpected column from the incoming schema. With schema evolution enabled, the pipeline can detect new fields, update the target schema, and continue processing while retaining Delta Lake's transactional guarantees. The solution therefore supports changing source data without sacrificing the managed-table architecture.