Professional Data EngineerEnsuring solution qualityMedium
A global logistics company uses BigQuery for analyzing shipment data, which involves joining large fact tables with smaller dimension tables. They frequently run complex SQL queries that perform aggregations and joins on millions or billions of rows. The data engineering team needs to optimize these queries to reduce execution time and associated costs, especially for interactive dashboards. Which BigQuery feature should they implement to pre-compute and store the results of common aggregation and join operations?
- ABigQuery Materialized Views
- BBigQuery BI Engine
- CBigQuery Clustering
- DBigQuery External Tables
Show answer & explanationAnswer & explanation
Correct answer: A. BigQuery Materialized Views
BigQuery Materialized Views are designed to pre-compute and store the results of frequently executed queries, especially those involving aggregations and joins. When the base tables change, materialized views are automatically refreshed, and BigQuery can transparently rewrite queries to use them, significantly reducing query execution time and costs for repetitive analytical workloads.
Why the other options are wrong
- B. BigQuery BI Engine is an in-memory analysis service that accelerates SQL queries, especially for dashboards, but it doesn't pre-compute and store results like materialized views.
- C. BigQuery Clustering improves query performance by co-locating data with similar values, but it doesn't pre-compute query results or reduce processing for repeated aggregations/joins.
- D. BigQuery External Tables allow querying data stored outside BigQuery, but do not pre-compute or store query results for performance optimization.
BigQuery Materialized Views
Pre-computed views that cache the results of a query, typically involving aggregations or joins, and are automatically refreshed when the base tables change.
- Improve query performance by reducing data scanned.
- Reduce query costs for repetitive workloads.
- BigQuery can automatically rewrite queries to use them.
Memory trick: Views Validate Values, Vanquish Volume.