Google Cloud’s New HDD Tier for Spanner: Slash Cold Storage Costs by 80%

Google Cloud’s Spanner Database Gets a Cost-Effective Makeover: Tiered Storage Arrives

By archyde.com news Desk

March 22, 2025

Spanner’s New HDD Tier: Big Savings for Big Data

Google Cloud has rolled out a important update too its Spanner distributed SQL database, introducing tiered storage based on a new HDD (Hard Disk Drive) option. This move, announced in early March 2025, promises to slash storage costs by up to 80% compared to the existing SSD (solid State Drive) option. For American businesses grappling with ever-expanding data volumes, this could translate into considerable savings without sacrificing data accessibility.

The core idea behind tiered storage is simple yet powerful: not all data needs the blazing-fast performance of SSDs. Older, less frequently accessed data – often referred to as “cold” data – can reside on cheaper, slower storage without impacting day-to-day operations. This allows companies to optimize their storage spending, allocating expensive SSD resources to “hot” data that demands low latency and high throughput.

Consider a retailer like Target, such as. Transactional data from the past few months, used for real-time inventory management and personalized recommendations, needs to be instantly accessible. Though, sales data from five years ago, primarily used for annual reports and long-term trend analysis, doesn’t require the same level of performance. Tiered storage allows Target to store the recent transactional data on SSDs and the older sales data on HDDs, considerably reducing their overall storage bill.

How Tiered Storage Works: Policy-driven Data Movement

Spanner’s tiered storage is policy-driven. This means that businesses define rules that dictate when and how data is moved between SSD and HDD tiers. These rules are implemented through asynchronous background processes, ensuring that data migration doesn’t interfere with ongoing operations.

Nonetheless of where the data resides, it remains accessible through standard SQL queries.This seamless integration is a key advantage, as it eliminates the need for complex data pipelines or request-level reconciliation. as Matthew Muckloo, software engineer at Google, and Piyush Mathur, group product manager at Google, explain:

Moving to choice types of storage typically requires complicated data pipelines and can impact the performance of the operational system. Manually separating data across storage solutions can result in inconsistent reads that require application-level reconciliation.Moreover,the separation imposes significant limits on how applications can query across current and historical data for things like responding to regulators; it also increases governance touchpoints that need to be audited.

This quote highlights a crucial benefit: Spanner’s tiered storage simplifies data management, maintaining data consistency and accessibility while lowering costs. This is particularly important for heavily regulated industries like finance and healthcare in the U.S., where access to historical data is frequently enough a legal requirement.

Storage tiering can be implemented at a granular level within Spanner, offering maximum versatility. Businesses can define policies at the database, table, column, or even secondary index level. For instance, a financial institution might move rarely accessed customer data like scanned check images to HDD, while keeping customer account balances and transaction history on SSD for fast access.

Implementing Tiered Storage: A Practical Example

Enabling tiered storage in Spanner involves creating a “locality group” that defines the storage options (SSD or HDD) and the policy for moving data between tiers. The ssd_to_hdd_spill_timespan parameter specifies how long data should remain on SSD before being moved to HDD.

Here’s an example of the SQL code used to create a locality group with an SSD to HDD spill policy:

     CREATE LOCALITY GROUP recent_on_ssd OPTIONS (storage="ssd", ssd_to_hdd_spill_timespan = '15d');
    

This code creates a policy that keeps data on SSD for 15 days before moving it to HDD. The minimum retention time on SSD is one hour.

Let’s imagine a healthcare provider using this feature. They could create a locality group for patient records, specifying that recent medical history (e.g., appointments, lab results) should reside on SSD for immediate access by doctors and nurses.Older medical records, used primarily for compliance and historical analysis, could then be automatically moved to HDD after a defined period, such as six months.

Spanner vs. the Competition: Addressing the Landscape of Cloud Databases

While Spanner’s tiered storage is a compelling feature, it’s critically important to consider the competitive landscape. Other cloud database providers, such as Amazon with DynamoDB, offer similar capabilities. However, the approach differs.

Amazon DynamoDB, for example, offers Standard and Standard-IA storage classes with varying costs for storage and retrieval. Unlike Spanner, DynamoDB abstracts away the underlying storage technology (SSD or HDD). While this simplifies management, it also provides less granular control over data placement.

Here’s a comparison of Spanner’s tiered storage with Amazon DynamoDB’s storage classes:

Feature	Google Spanner	Amazon DynamoDB
Storage Tiers	Explicit SSD and HDD tiers	Standard and standard-IA storage classes
Storage Technology Visibility	Users are aware of underlying storage (SSD/HDD)	Underlying storage is abstracted
Policy Granularity	Database, table, column, secondary index	Table level
SQL Dialects	GoogleSQL and PostgreSQL	DynamoDB API

The choice between Spanner and DynamoDB depends on the specific needs and priorities of the institution. Spanner offers more granular control and SQL compatibility while DynamoDB provides a simpler, more abstracted approach.

The Bottom line: Cost Savings and Performance Optimization

Google Spanner’s new tiered storage option represents a significant step forward in cloud database management. By offering a cost-effective HDD tier and policy-driven data movement, Spanner empowers American businesses to optimize their storage spending without compromising data accessibility or consistency.

With support for both GoogleSQL and PostgreSQL dialects and availability in all Google Cloud regions, Spanner’s tiered storage is poised to become a popular choice for organizations seeking to balance performance and cost in their cloud database deployments. Companies can monitor HDD usage through System Insights.

For U.S.companies, this translates into a real prospect to reduce IT budgets, improve efficiency, and gain a competitive edge in today’s data-driven economy. As data volumes continue to explode, solutions like Spanner’s tiered storage will become increasingly critical for managing and leveraging the power of facts.

What do you think the most underestimated aspect of moving to a tiered storage solution will be for companies adopting this new feature?

Interview: Leveraging Google Spanner’s Tiered Storage for Cost Optimization

by Archyde News Desk

march 22, 2025

Interview with Amelia Stone, Lead Cloud Architect at Zenith Solutions

Archyde: Welcome, Amelia! Thanks for joining us today. Google Cloud’s recent introduction of tiered storage for Spanner has been causing quite a stir.As a leading cloud architect, what’s your initial assessment of this announcement?

Amelia Stone: Thanks for having me. It’s a game-changer, frankly. The ability to leverage HDD storage within Spanner, at a much lower cost than SSD, opens up significant opportunities for optimizing storage expenses. For businesses managing large datasets, this is a welcome relief.

Archyde: Absolutely. The potential for 80% cost savings is significant.coudl you elaborate on how businesses like Zenith Solutions can actually implement this tiered storage strategy?

Amelia Stone: Certainly. spanner’s policy-driven approach is key.We define policies using locality groups,specifying how data moves between SSD and HDD. As an example,we might set a rule to move data older than six months to HDD,keeping more recent,frequently accessed data on SSD. The granular control at the database, table, or even column level is fantastic.The example given in the documentation of the retention time on SSD for the CREATE LOCALITY GROUP command is a great starting point to quickly implement a similar solution.

Archyde: That level of control sounds extraordinary. What are the practical benefits you foresee for companies in different sectors, like finance or healthcare?

amelia Stone: In finance, we can move historical transaction data to HDD, while keeping current account balances on SSD for rapid access. In healthcare,we can store recent patient records on SSD for doctors,and older records on HDD for compliance. This balance of performance and cost efficiency is key to maximizing our client’s resources. It’s all about finding the right balance.

Archyde: The article mentioned a comparison with Amazon DynamoDB. What are your thoughts on spanner’s approach versus the competition in this space?

amelia Stone: While DynamoDB offers storage classes, Spanner provides more explicit control over the underlying storage technology. We can actually see and know that we are using HDD or SSD. This gives us greater versatility to fine-tune performance and cost based on our specific request needs. Plus, the SQL compatibility provided by Spanner is a huge win in terms of ease of use and integration with existing systems.

archyde: Monitoring HDD usage seems vital hear. How can businesses make sure they are properly running and optimized with this new feature?

Amelia Stone: Google offers tools like “System Insights” that will provide clear visibility into HDD usage. this will allow for a extensive analysis of your storage spending, identifying areas for further refinement and cost reduction. We are still exploring the extent of data that can be derived from these sources.

Archyde: what’s one key piece of advice you’d offer to businesses considering adopting Spanner’s tiered storage?

Amelia Stone: Start by carefully analyzing your data access patterns.Identify which data is “hot” and requires SSD performance, and which data is “cold” and suitable for HDD. Then, create your locality groups and policies accordingly. Don’t be afraid to experiment, and always monitor performance and costs to ensure optimal results. What do you think the most underestimated aspect of moving to a tiered storage solution will be for companies adopting this new feature?

Archyde: Excellent advice, Amelia! Thank you for sharing your insights. This has been incredibly helpful. We appreciate your time.

Amelia Stone: My pleasure.