Question

An industrial monitoring platform collects sensor readings from 500,000 devices, each emitting one metric every second (roughly 43 billion writes per day). Analysts need single-digit-millisecond lookups of the most recent readings for any given device over a specified time range, and the workload will grow to millions of devices. Which storage system and design best fits these requirements?

Accepted Answer

Cloud Bigtable with a row key of deviceID#reverseTimestamp, storing metrics in column families

Answer

Firestore in Native mode with one document per reading, indexed by device and timestamp fields

Answer

Cloud SQL for PostgreSQL with a composite index on (device_id, reading_time) and read replicas

Answer

BigQuery with a table partitioned by ingestion date and clustered on device_id