Data Analysis & Reporting Flashcards

What is the primary advantage of using BigQuery's BI Engine?

Answer: It provides in-memory analysis for sub-second query response times in BI tools

BI Engine is an in-memory analysis service that accelerates BigQuery queries for BI tools like Looker Studio, delivering sub-second response times.

You want to identify the top 5 products by revenue in a BigQuery query. Which SQL clause should you use?

Answer: ORDER BY revenue DESC LIMIT 5

ORDER BY revenue DESC sorts results from highest to lowest revenue, and LIMIT 5 returns only the top 5 rows.

In Cloud Dataflow, what is a 'PCollection'?

Answer: An immutable distributed dataset that represents pipeline data

A PCollection is the fundamental data abstraction in Apache Beam/Dataflow — an immutable, distributed collection of elements processed by the pipeline.

Which BigQuery function would you use to calculate a 7-day moving average of daily sales?

Answer: AVG() OVER (ORDER BY date ROWS BETWEEN 6 PRECEDING AND CURRENT ROW)

Window functions with AVG() and a frame clause (ROWS BETWEEN 6 PRECEDING AND CURRENT ROW) compute a rolling average over the specified window.

What is the role of Cloud Pub/Sub in a data analytics pipeline?

Answer: It acts as a message queue to ingest and buffer streaming data

Pub/Sub is a messaging service that decouples data producers from consumers, buffering streaming events before downstream processing by Dataflow or other services.

In Looker Studio, what does 'blending' data sources allow you to do?

Answer: Combine data from multiple sources into a single chart

Data blending in Looker Studio joins data from different sources (e.g., Google Analytics + BigQuery) within a single visualization using a common join key.

Which BigQuery pricing model charges based on the amount of data processed by each query?

Answer: On-demand pricing

On-demand pricing in BigQuery charges $5 per TB of data processed by queries, making query optimization important for cost control.