Databricks Updated Databricks-Certified-Data-Engineer-Associate Exam Questions and Answers by hasan

A data engineer can create a multi-task job in Databricks that consists of multiple tasks that run in a specific order. Each task can have one or more dependencies, which are other tasks that must run before the current task. The Depends On field of a new Databricks Job Task allows the data engineer to specify the dependencies of the task. The data engineer should select a task in the Depends On field when they want the new task to run only after the selected task has successfully completed. This can help the data engineer to create a logical sequence of tasks that depend on each other’s outputs or results. For example, a data engineer can create a multi-task job that consists of the following tasks:

Task A: Ingest data from a source using Auto Loader

Task B: Transform the data using Spark SQL

Task C: Write the data to a Delta Lake table

Task D: Analyze the data using Spark ML

Task E: Visualize the data using Databricks SQL

In this case, the data engineer can set the dependencies of each task as follows:

Task A: No dependencies

Task B: Depends on Task A

Task C: Depends on Task B

Task D: Depends on Task C

Task E: Depends on Task D

This way, the data engineer can ensure that each task runs only after the previous task has successfully completed, and the data flows smoothly from ingestion to visualization.

The other options are incorrect because they do not describe valid scenarios for selecting a task in the Depends On field. The Depends On field does not affect the following aspects of a task:

Whether the task needs to be replaced by another task

Whether the task needs to fail before another task begins

Whether the task has the same dependency libraries as another task

Whether the task needs to use as little compute resources as possible References: Create a multi-task job, Run tasks conditionally in a Databricks job, Databricks Jobs.

For large-scale batch ETL workloads , Databricks documentation recommends using job clusters that are created specifically for a job run and terminated automatically when the job completes. A job cluster with autoscaling enabled provides the best balance of performance, reliability, and cost efficiency for long-running nightly pipelines. Autoscaling allows the cluster to dynamically add or remove worker nodes based on the workload demands, ensuring sufficient parallelism to process very large JSON datasets efficiently while avoiding overprovisioning when demand decreases. This is especially important when processing raw data into Delta tables, where shuffle-heavy transformations and writes benefit from multiple workers. Single-node clusters (option B) are not suitable for very large volumes of data and risk excessive runtimes or job failures. High-concurrency clusters (option C) are optimized for interactive and concurrent SQL queries, not long-running batch ETL jobs. Always-on all-purpose clusters (option D) increase costs unnecessarily and are intended for interactive development, not scheduled production pipelines. Databricks best practices clearly position autoscaling job clusters as the preferred solution for reliable, cost-effective batch ETL in production on Databricks.

The engineer should inspect the job’s maximum concurrent-runs configuration and its queueing setting. max_concurrent_runs controls how many active runs of the same job can execute simultaneously. When that limit has already been reached, Databricks can skip the newly triggered run if queueing is disabled. When queueing is enabled, the additional run waits until capacity becomes available instead of being skipped. Spot-instance availability might delay or prevent compute startup, but it would not normally produce a job-level concurrency message. SQL warehouse permissions affect SQL task execution after a run begins, while timeout_seconds determines how long a task may run before timing out. Therefore, option C directly addresses the reported run state. This candidate was also compared against the existing Word question bank.

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