Microsoft DP-750 Exam With Confidence Using Practice Dumps

The correct answer is B — No.

A Databricks Access Connector is an Azure resource that provides a managed identity for Databricks to authenticate to Azure Storage services. It is an authentication bridge — nothing more. Creating one doesn't register any external database, doesn't create any Unity Catalog objects representing DB1, and doesn't enable querying of SQL Server data from Databricks.

An Access Connector is a prerequisite for setting up storage credentials and external locations in Unity Catalog (to access ADLS Gen2, for example), but it has no role in Lakehouse Federation or foreign catalog creation. It cannot expose an external database's schemas and tables in Unity Catalog alongside native objects.

The correct solution for this scenario is a foreign catalog (Q47), which requires a connection object pointing to DB1 — not an Access Connector.

The solution requires spark.readStream with format('cloudFiles') for Auto Loader, paired with .writeStream using mergeSchema=true and a checkpointLocation.

Auto Loader's cloudFiles source incrementally processes new JSON files without rescanning the entire directory. The mergeSchema option handles schema drift — when sensors add new fields, the target Delta table schema expands automatically instead of throwing a parse error. This directly addresses Contoso's requirement to 'support schema drift.'

The checkpointLocation is what gives the pipeline its resilience. Databricks writes the stream's committed offset and schema state to that path. If the cluster restarts, the engine reads the checkpoint and picks up exactly where it left off — no events are reprocessed, satisfying 'exactly-once semantics' and 'resume processing after failures without reprocessing the data.'

Without a checkpoint, the stream would restart from the beginning on every cluster bounce, which is precisely the problem Contoso is trying to eliminate.

The correct answer is B — No.

This is a common Python-to-PySpark trap. In pure Python, comparing a value to None with != works as expected. In PySpark, null comparisons follow SQL null semantics: any comparison involving NULL returns NULL (not True or False). So df.filter(df.order_amount != None) doesn't evaluate to True for non-null rows — the comparison itself returns NULL for null values, and Spark interprets NULL in a filter as False, effectively dropping null rows. But the behaviour is undefined in edge cases and is not the documented approach.

More practically, Python's None and Spark's SQL NULL are different concepts. PySpark Column objects don't support Python's native equality/inequality semantics for null checking. The result is typically an empty DataFrame or incorrect filtering behaviour.

Always use .isNotNull() or .isNull() for null checks in PySpark column expressions. These methods are specifically designed for SQL-null-aware comparisons and produce correct, predictable results.