professional-cloud-data-engineer
Prepare and test your skills
Prepare and test your skills
Worked example. The correct answer is already marked and every option is explained below, so there is nothing to select here. To answer questions yourself, start the free trial.
A data engineering team at an enterprise IoT company is architecting a high-volume BigQuery data warehouse table that ingests 2 TB of telemetry data daily. The data contains an event_timestamp, a high-cardinality device_id, a low-cardinality device_type, and sensor metric payloads.
The analytical workload has the following characteristics:
device_id values.device_type.Which table design strategy should the data engineer implement to achieve optimal query performance and cost efficiency?
Table partitioning divides a large table into smaller, manageable segments based on a date, timestamp, or integer range column. Clustering sorts the underlying columnar data based on one or more user-specified columns (up to four) within each partition, colocating related data into granular storage blocks.
event_timestamp ensures that queries filtering on recent date windows (e.g., past 7–30 days) perform partition pruning, eliminating unnecessary partition scans entirely.device_id): Clustering by device_id sorts and organizes records into distinct storage blocks, enabling BigQuery to skip scanning irrelevant data blocks (block pruning).device_type): Including device_type in the clustering specification colocates identical device types together within the blocks, speeding up aggregate calculations and group-by operations.Combining time-based partitioning with multi-column clustering leverages BigQuery's two primary storage organization mechanisms simultaneously. This provides the lowest possible bytes scanned for time-series analytical workloads.
Keep the momentum going with these hand-picked practice scenarios
Want more questions like this?
Get a free certification question every week.