Today, we are excited to announce enhancements to the borderless Lakehouse, our answer to how data engineers, data scientists, and increasingly, AI agents, can query governed data directly where it lives.
To reason accurately and automate complex enterprise workflows, agents and data consumers of all types need fast, unified access to an organization’s complete data estate, joining customer records, transaction logs, and operational telemetry across clouds. However, modern enterprise data is rarely confined to a single location; data estates often span Amazon S3, Azure Data Lake Storage (ADLS), Google Cloud Storage, operational databases, and SaaS platforms like Salesforce, SAP, and Workday. Historically, uniting these distributed datasets required brittle ETL pipelines, duplicated storage, and prohibitive cross-cloud data transfer costs.
We introduced the borderless Lakehouse earlier this year to let organizations query and activate data in place across clouds. By adopting the Apache Iceberg REST catalog specification, we federate directly to catalogs such as Databricks Unity Catalog, AWS Glue, and Snowflake Horizon. We also introduced Partner Cross-Cloud Interconnect to establish high-bandwidth, private links to other cloud providers, lowering per-gigabyte transfer costs compared to the public internet.
Today, we are taking multi-cloud efficiency a step further by optimizing how much data needs to be transferred across the wire in the first place.
We are excited to announce two new features to help further reduce costs of querying cross-cloud data. First, the preview of cross-cloud caching for Lakehouse transparently accelerates cross-cloud queries in BigQuery and cuts remote transfer costs by caching frequently accessed data locally in Google Cloud. Combining standard Iceberg columnar compression with cross-cloud caching means you often only need to transfer under 5% of the data you process across clouds, which helps lower the Total Cost of Ownership (TCO) to make cross-cloud analytics and AI viable at enterprise scale. In addition, BigQuery cross-cloud connections are also available in preview to query non-Iceberg data in other clouds and accelerate workloads.
How cross-cloud caching works
Cross-cloud caching meets enterprise performance and security requirements with no knobs to turn or storage to manage to accelerate your queries. Some of the mechanisms used under the hood are:
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Sub-file block granularity: Instead of transferring entire multi-gigabyte files across clouds when a query touches only a few columns, cross-cloud caching operates at the sub-file block level for columnar formats like Apache Parquet. BigQuery caches only the specific column chunks and dictionary pages projected by the query. On a cache miss, BigQuery fetches the needed data from the remote cloud to answer the query, and saves a local copy in the cache for future queries, drastically cutting network transfer and latency on repeated workloads.
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Default encryption at rest: Cached data blocks are encrypted at rest by default using Google-managed encryption keys (GMEK) so that temporary cache storage maintains the same enterprise-grade security posture as native BigQuery storage without extra overhead.
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Tenant and regional isolation: Cache entries are strictly partitioned by project and catalog boundaries to help prevent cross-tenant data exposure. Lakehouse anchors both the local cache and query execution strictly to the configured Google Cloud region (e.g., us-east4) to support compliance with regional data residency requirements when querying remote clouds.
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Freshness checks: Multi-cloud caching often forces a trade-off between speed and freshness. To avoid stale reads, BigQuery fetches remote object metadata before using cached data to ensure the data hasn’t changed and the user still has access. Any upstream table modification prompts BigQuery to fetch new files, while unreferenced cached blocks expire automatically, delivering local query speed with single-source-of-truth accuracy.
For more details on caching mechanics, statistics counters, and regional considerations, see the Lakehouse intelligent caching documentation.
Cross-cloud caching in action
So how does this work in day-to-day operations? Consider an e-commerce team querying a 10 TiB Iceberg sales table (aws_lakehouse_catalog.sales.web_sales) in Amazon S3, federated into Lakehouse from Databricks Unity Catalog. During evening promotional drops (8:00–9:00 PM), analysts query historical transactions to identify which storefronts drive peak volume and revenue among high-intent demographics:
