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Egress considerations

Delta Sharing supports cross-cloud and cross-region data sharing without requiring data replication. However, when data moves across cloud boundaries or between regions, cloud providers charge egress fees to the provider when recipients read shared data. For detailed guidance, see Monitor and manage Delta Sharing egress costs.

Reduce data volume​

Partition filtering​

Use partitioned table sharing to deliver only relevant subsets of data:

ALTER SHARE my_share
ADD TABLE catalog.schema.sales
PARTITION (territory = 'north_america', year >= 2024);

Change Data Feed​

Enable Change Data Feed (CDF) so consumers pull only new or modified records instead of full table refreshes.

History sharing trade-offs​

Sharing tables WITH HISTORY enables time travel and CDF, but increases accessible data volume:

  • WITH HISTORY: Better performance for incremental reads, but recipients can access historical data
  • Without history: Smaller data footprint, but recipients must read full snapshots

Reduce transfer costs​

Cloudflare R2​

Host or replicate shared data in Cloudflare R2 to eliminate egress fees entirely. Data in R2 can be shared across any cloud or region without outbound transfer charges.

Regional replication​

Replicate data to the same cloud and region where your primary customers operate. Use DEEP CLONE with Workflows to automate incremental replication.

VPC endpoints​

Encourage recipients to use VPC gateway or interface endpoints for S3 instead of NAT gateways. This reduces costs and enhances security for in-region access.

Monitor and optimize​

Use the AWS egress monitoring notebook to identify where costs are incurred and track data transfer patterns. This helps detect high-volume consumers or cross-region traffic driving unexpected costs.

Pattern-specific considerations​

PatternEgress impact
D2D (same region)Minimal—data stays within Databricks infrastructure
D2D (cross-region)Standard cloud egress fees apply
D2OHigher—external recipients may not leverage CDF or other optimizations

Cloud pricing calculators​

Estimate your actual egress costs using the official cloud provider calculators:

What's next​