Azure Data Monitoring and Optimization Flashcards

In Azure Data Lake Storage Gen2, what is the recommended file size range for optimal analytics performance?

Answer: 256 MB–1 GB

Analytics frameworks like Spark perform best with files in the 256 MB–1 GB range, as very small files create excessive metadata overhead.

What is the purpose of statistics in Azure Synapse Analytics dedicated SQL pool?

Answer: To provide the query optimizer with data distribution information for generating efficient execution plans

Statistics describe column value distribution and help the Synapse query optimizer choose optimal join strategies, aggregation methods, and data movement operations.

In Azure Databricks, what is the purpose of Z-ordering a Delta table?

Answer: To co-locate related data in the same set of files to improve filter predicate performance

Z-ordering organizes data in files so that rows with similar values in the Z-ordered columns are physically co-located, improving data skipping for filter queries.

What Azure Data Factory monitoring feature allows you to view the detailed execution status and duration of each activity within a pipeline run?

Answer: Activity run history in Monitor tab

The Monitor tab in ADF shows pipeline and activity run history, including status, duration, input/output, and error details for each activity execution.

Which Azure Monitor feature allows you to define automated actions—such as sending an email or triggering a runbook—when a metric crosses a threshold?

Answer: Action groups with alert rules

Alert rules evaluate metric or log conditions and trigger action groups that can send emails, call webhooks, or execute automation runbooks.

What does enabling diagnostic settings on an Azure data service do?

Answer: Routes resource logs and metrics to a destination like Log Analytics, Storage, or Event Hubs

Diagnostic settings route a resource's platform logs and metrics to one or more destinations (Log Analytics, Storage, Event Hubs) for analysis and archiving.