Databricks Certified Data Engineer Professional 問題集 : Certified-Data-Engineer-Professional

Although the Databricks Utilities Secrets module provides tools to store sensitive credentials and avoid accidentally displaying them in plain text users should still be careful with which credentials are stored here and which users have access to using these secrets.
Which statement describes a limitation of Databricks Secrets?

• A. Secrets are stored in an administrators-only table within the Hive Metastore; database administrators have permission to query this table by default.
• B. Account administrators can see all secrets in plain text by logging on to the Databricks Accounts console.
• C. Iterating through a stored secret and printing each character will display secret contents in plain text.
• D. Because the SHA256 hash is used to obfuscate stored secrets, reversing this hash will display the value in plain text.
• E. The Databricks REST API can be used to list secrets in plain text if the personal access token has proper credentials.

When evaluating the Ganglia Metrics for a given cluster with 3 executor nodes, which indicator would signal proper utilization of the VM's resources?

• A. CPU Utilization is around 75%
• B. The five Minute Load Average remains consistent/flat
• C. Bytes Received never exceeds 80 million bytes per second
• D. Total Disk Space remains constant
• E. Network I/O never spikes

In order to prevent accidental commits to production data, a senior data engineer has instituted a policy that all development work will reference clones of Delta Lake tables. After testing both deep and shallow clone, development tables are created using shallow clone. A few weeks after initial table creation, the cloned versions of several tables implemented as Type 1 Slowly Changing Dimension (SCD) stop working. The transaction logs for the source tables show that vacuum was run the day before.
Why are the cloned tables no longer working?

• A. Because Type 1 changes overwrite existing records, Delta Lake cannot guarantee data consistency for cloned tables.
• B. The metadata created by the clone operation is referencing data files that were purged as invalid by the vacuum command
• C. Running vacuum automatically invalidates any shallow clones of a table; deep clone should always be used when a cloned table will be repeatedly queried.
• D. Tables created with SHALLOW CLONE are automatically deleted after their default retention threshold of 7 days.
• E. The data files compacted by vacuum are not tracked by the cloned metadata; running refresh on the cloned table will pull in recent changes.

A Spark job is taking longer than expected. Using the Spark UI, a data engineer notes that the Min, Median, and Max Durations for tasks in a particular stage show the minimum and median time to complete a task as roughly the same, but the max duration for a task to be roughly 100 times as long as the minimum.
Which situation is causing increased duration of the overall job?

• A. Task queueing resulting from improper thread pool assignment.
• B. Network latency due to some cluster nodes being in different regions from the source data
• C. Skew caused by more data being assigned to a subset of spark-partitions.
• D. Credential validation errors while pulling data from an external system.
• E. Spill resulting from attached volume storage being too small.

Which statement describes a key benefit of an end-to-end test?

• A. It closely simulates real world usage of your application.
• B. It provides testing coverage for all code paths and branches.
• C. It makes it easier to automate your test suite
• D. It pinpoint errors in the building blocks of your application.