Based on the official AWS re:Invent 2025 announcement

What Are S3 Tables?

Amazon S3 Tables is a purpose-built storage solution for Apache Iceberg tables that delivers up to 3x faster query performance and up to 10x higher transactions per second compared to self-managed Iceberg tables on S3.

At re:Invent 2025, AWS announced two critical features that dramatically improve cost efficiency and data resilience for data lake workloads.

Feature 1: Intelligent Tiering for S3 Tables

The most significant cost optimization feature announced is automatic Intelligent Tiering for S3 Tables.

How It Works

S3 Tables now automatically moves data between storage tiers based on access patterns:

  • Frequent Access Tier: For data accessed regularly (standard S3 pricing)
  • Infrequent Access Tier: For data accessed less than once per month (68% cost reduction)
  • Archive Instant Access: For rarely accessed data (95% cost reduction)

Cost Savings Breakdown

Storage Tier Cost per GB/Month Savings vs Standard Best For
Frequent Access $0.023 Baseline Hot data, daily queries
Infrequent Access $0.0125 68% savings Monthly access
Archive Instant Access $0.004 95% savings Compliance, historical data

Key Benefits for FinOps

  • Zero Configuration: Automatic tiering with no manual intervention
  • No Retrieval Delays: Instant access to archived data (unlike Glacier)
  • Transparent Pricing: No monitoring or automation fees
  • Optimized for Analytics: Works seamlessly with Athena, EMR, and Spark

Real-World Cost Example

Scenario: 100 TB data lake with typical access patterns

  • 40 TB hot data (accessed daily)
  • 30 TB warm data (accessed monthly)
  • 30 TB cold data (accessed quarterly)

Without Intelligent Tiering:

100 TB × $0.023/GB = $2,300/month

With Intelligent Tiering:

40 TB × $0.023/GB = $920/month (hot)
30 TB × $0.0125/GB = $375/month (warm)
30 TB × $0.004/GB = $120/month (cold)
Total = $1,415/month

Monthly Savings: $885 (38% reduction)
Annual Savings: $10,620

Feature 2: Cross-Region Replication

S3 Tables now supports cross-region replication for disaster recovery and compliance requirements.

How It Works

Automatically replicate your Iceberg tables across AWS regions with:

  • Continuous, asynchronous replication
  • Metadata and data synchronization
  • Configurable replication rules
  • Support for multiple destination regions

Use Cases

  • Disaster Recovery: Maintain business continuity with regional failover
  • Data Residency: Meet compliance requirements for data locality
  • Global Analytics: Reduce query latency for distributed teams
  • Multi-Region Applications: Support applications deployed across regions

Cost Considerations

Replication costs include:

  • Data Transfer: $0.02/GB for cross-region transfer
  • Storage: Standard S3 Tables pricing in destination region
  • Replication Requests: PUT/COPY request pricing

Cost Optimization Tip: Combine replication with Intelligent Tiering in the destination region to minimize storage costs for replicated data.

FinOps Best Practices

1. Enable Intelligent Tiering by Default

For all new S3 Tables, enable Intelligent Tiering from day one:

aws s3tables create-table \
    --namespace my-namespace \
    --name my-table \
    --storage-class INTELLIGENT_TIERING

2. Monitor Access Patterns

Use CloudWatch metrics to understand data access patterns:

  • Track tier transitions
  • Identify optimization opportunities
  • Validate cost savings

3. Optimize Replication Strategy

  • Replicate only critical tables
  • Use selective replication rules
  • Consider replication timing (off-peak hours)
  • Enable Intelligent Tiering on replicas

4. Leverage Lifecycle Policies

Combine S3 Tables features with lifecycle policies:

  • Archive old partitions automatically
  • Delete obsolete data
  • Transition to Glacier for long-term retention

5. Right-Size Your Data Lake

  • Implement data retention policies
  • Remove duplicate data
  • Compress data efficiently (Parquet, ORC)
  • Partition tables strategically

Migration Guide

Existing S3 Tables Users

Enable Intelligent Tiering on existing tables:

  1. Navigate to S3 Tables console
  2. Select your table
  3. Choose "Edit storage settings"
  4. Enable "Intelligent Tiering"
  5. Confirm changes

Note: Existing data will be analyzed and tiered automatically over the next 30 days.

Self-Managed Iceberg Users

Migrate to S3 Tables to unlock these features:

  1. Create S3 Tables namespace
  2. Use AWS Glue or Spark to migrate metadata
  3. Copy data to S3 Tables bucket
  4. Enable Intelligent Tiering
  5. Update query engines to use S3 Tables

Performance Impact

Intelligent Tiering maintains query performance:

  • No Latency: All tiers provide instant access
  • Transparent: Query engines see no difference
  • Optimized I/O: S3 Tables handles tier management

Availability

Both features are now available in all regions where S3 Tables is supported:

  • US East (N. Virginia, Ohio)
  • US West (Oregon, N. California)
  • Europe (Ireland, Frankfurt, London)
  • Asia Pacific (Singapore, Sydney, Tokyo)

Conclusion

The addition of Intelligent Tiering and cross-region replication to S3 Tables represents a major advancement in data lake cost optimization. Organizations can now:

  • Reduce storage costs by up to 95% with automatic tiering
  • Improve data resilience with cross-region replication
  • Maintain query performance with instant access to all tiers
  • Simplify operations with zero-configuration automation

For FinOps teams managing large-scale data lakes, these features deliver immediate, measurable cost savings without operational overhead. The combination of performance, cost optimization, and resilience makes S3 Tables the optimal choice for Apache Iceberg workloads on AWS.

Next Steps

  1. Audit your current data lake storage costs
  2. Identify tables suitable for S3 Tables migration
  3. Enable Intelligent Tiering on existing S3 Tables
  4. Implement replication for critical datasets
  5. Monitor savings using Cost Explorer