Amazon Athena Federated Query | Deep Dive.

Amazon Athena Federated Query - Deep Dive.

Scope:

• Intro,
• The Concept: Athena Federated Query,
• How it Works,
• Architecture & Key Components,
• Flow,
• Supported Data Sources,
• Use Cases,
• Performance & Optimization,
• Security,
• Pricing,
• Best Practices.

Intro:

• Amazon Athena Federated Query is built on top of the standard Athena.
• But it extends querying capabilities beyond S3.

1. The Concept: Athena Federated Query

Athena Federated Query enables twtech to run SQL queries across multiple data sources, not just Amazon S3.

• Uses the same Presto-based Athena engine.
• Supports structured, semi-structured, and unstructured data.
• Queries are executed in-place — data is read directly from the source.
• Great for single-pane-of-glass analytics across diverse stores.

2. How it Works

1. Data Sources: twtech can connect Athena to RDS, Redshift, DynamoDB, Aurora, CloudWatch Logs, and even external sources like MySQL, PostgreSQL, and SaaS apps.
2. Connectors: Uses Athena Query Federation SDK and Lambda-based data source connectors.
• AWS provides prebuilt connectors (S3, Redshift, DynamoDB, DocumentDB, CloudWatch, etc.).
• twtech can also build custom connectors for any JDBC-compliant source.
3. Glue Data Catalog: Manages schemas and table definitions across sources.
4. Query Execution: Athena’s Presto engine coordinates with connectors → connectors fetch data from the source → results streamed back into Athena.
5. Outputs: Results stored in S3, and accessible to BI tools (QuickSight, Tableau, Power BI..(Business Intelligence)).

3. Architecture & Key Components:

• Athena Engine (Presto/Trino)
• AWS Glue Data Catalog (metadata)
• Federated Query Connectors (Lambda functions)
• Source Databases (RDS, Redshift, DynamoDB, external JDBC, SaaS APIs)
• S3 (query results storage)
• BI Tools (QuickSight, Tableau, etc.)

Flow:

Athena Query ➝ Glue Catalog ➝ Presto Engine ➝ Lambda Connector ➝ Source DB ➝ Results ➝ S3 + BI(Business Intelligence) Tools.

4. Supported Data Sources

Out-of-the-box Athena Federation Connectors include:

• AWS Sources:
• DynamoDB
• RDS (MySQL, PostgreSQL)
• Aurora
• Redshift
• DocumentDB
• CloudWatch Logs
• CloudWatch Metrics
• External Sources:
• MySQL
• PostgreSQL
• SAP HANA
• Teradata
• Oracle
• Google BigQuery
• Snowflake
• Custom JDBC

5. Use Cases

• Unified Analytics: Query across S3 (data lake) + DynamoDB (NoSQL) + RDS (transactional DB).
• Ad-Hoc Queries: Business analysts query without ETL pipelines.
• Data Lake Federation: Extend your data lake to operational databases.
• Cross-System Joins: Example → Join CloudWatch Logs with RDS transactions for troubleshooting.
• Compliance & Audits: Query multiple systems for reports without data duplication.

6. Performance & Optimization

• Pushdown Processing: Whenever possible, queries are pushed down to the source (e.g., WHERE clauses applied in the DB).
• Partitioning in Source: Helps minimize scanned data.
• Limit Data Movement: Joins across sources may cause large data transfers. Best to pre-aggregate in source systems.
• Connector Tuning: Lambda-based connectors need concurrency and timeout tuning for large queries.
• Caching / CTAS: Store federated results in S3 (Parquet/ORC) for repeat queries.

7. Security

• IAM + Lake Formation: Controls access to Athena and connectors.
• Encryption: Data in transit via TLS; results encrypted in S3.
• Granular Access: Use fine-grained permissions in Lake Formation & source DB.

8. Pricing

• Athena charges $5 per TB scanned, across all federated sources.
• Additional charges:
• Lambda execution time (for connectors).
• Data transfer costs if cross-region queries are executed.

9. Best Practices

• Use federated queries for exploration & occasional joins, not heavy analytics.
• For repeated workloads → export data to S3 in Parquet via CTAS (Call to Action… a clear instruction designed to get a user to do something).
• Keep connectors optimized (configure memory, concurrency, timeout).
• Secure and audit with CloudTrail + Lake Formation.
• Monitor query performance with Athena Workgroups + CloudWatch.

Final thoughts:

• Athena Federated Query = Athena + Lambda Connectors + Glue Catalog → lets twtech query any data source (cloud DBs, logs, SaaS, S3) with one SQL interface, without ETL(Extract, Transform, Load) pipelines.