Federated Query
A federated query is a single query that pulls and combines data from multiple separate databases or data sources as if they were one system.
In Depth
Federation answers questions that no single database can: joining customers in Postgres against support tickets in another system, in one query, without first copying everything into a warehouse. Engines like Trino and Presto, and features like Postgres foreign data wrappers, make this possible by translating one query into sub-queries against each source and stitching the results. The appeal is skipping ETL; the catch is performance—cross-source joins move data over the network and can be slow. Federation suits occasional cross-system questions, while frequently combined data usually still belongs in a warehouse.
How AI for Database Helps
AI for Database connects to each of your databases directly, giving you one plain-English interface across all of them without building a federation layer.
Related Terms
Multi-Database Querying
Multi-database querying is the ability to connect to and query several different databases—often different engines entirely—from a single tool or interface.
Data Warehouse
A centralized repository optimized for analytical queries across large volumes of historical data from multiple sources.
ETL
Extract, Transform, Load—a data integration process that moves data from source systems into a data warehouse.
Data Pipeline
An automated series of data processing steps that moves and transforms data from sources to destinations.
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