Exactprep DP-600 Questions

When you need to return all rows that are present in both tables, you use a full outer join. This type of join combines the results of both left and right outer joins and returns all rows from both tables, with matching rows from both sides where available. If there is no match, the result is NULL on the side of the join where there is no match.

References: Information about joins and their use in querying data in a lakehouse can be typically found in the SQL and data processing documentation of the Fabric tenant or lakehouse solutions.

The results will form a hierarchy of folders for each partition key. - Yes

The resulting file partitions can be read in parallel across multiple nodes. - Yes

The resulting file partitions will use file compression. - No

Partitioning data by columns such as year, month, and day, as shown in the DataFrame write operation, organizes the output into a directory hierarchy that reflects the partitioning structure. This organization can improve the performance of read operations, as queries that filter by the partitioned columns can scan only the relevant directories. Moreover, partitioning facilitates parallelism because each partition can be processed independently across different nodes in a distributed system like Spark. However, the code snippet provided does not explicitly specify that file compression should be used, so we cannot assume that the output will be compressed without additional context.

References =

DataFrame write partitionBy

Apache Spark optimization with partitioning

The code embeds an existing Power BI report. - No

The code creates a Power BI report. - Yes

The code displays a summary of the DataFrame. - Yes

The code provided seems to be a snippet from a SQL query or script which is neither creating nor embedding a Power BI report directly. It appears to be setting up a DataFrame for use within a larger context, potentially for visualization in Power BI, but the code itself does not perform the creation or embedding of a report. Instead, it's likely part of a data processing step that summarizes data.

References =

Introduction to DataFrames - Spark SQL

Power BI and Azure Databricks

Remove the files: Run the VACUUM command on a schedule.

Combine the files: Set the optimizeWrite table setting. or Run the OPTIMIZE command on a schedule.

To remove files that are no longer used, the VACUUM command is used in Delta Lake to clean up invalid files from a table. To combine smaller files into larger ones, you can either set the optimizeWrite setting to combine files during write operations or use the OPTIMIZE command, which is a Delta Lake operation used to compact small files into larger ones.