Google Cloud Introduces HDD Tier for Spanner Database, Cutting Cold Storage Costs by 80%
InfoQ, Saturday, March 22nd, 2025
Google has recently introduced tiered storage for Spanner, its distributed SQL database on Google Cloud. This tiered storage is based on a new HDD storage option that is 80% cheaper than the existing SSD option, allowing for cost optimization of older data while minimizing the overhead associated with traditional data migration.
While the default SSD tier is designed for data that requires high throughput and low latency, the new HDD tier is designed for larger datasets that are infrequently accessed or not latency-sensitive. Storage tiering is policy-driven, with asynchronous background processes automatically moving data from SSD to HDD as part of maintenance tasks and according to user-defined policies. Regardless of the storage tier, SQL queries can access data across both SSD and HDD tiers, with backup policies applied consistently across all data.