Federated Query Optimization

A method builds a regression model for predicting processing times for federated queries using a variety of data sources. The method includes obtaining federated queries (e.g., from benchmarks), and generates a plurality of federated query plans for each federated query. Each federated query plan corresponds to executing a respective federated query using a respective data source as the federation engine. The method includes forming feature vectors for each federated query plan based on cost estimations for executing the respective federated query plan and cost estimations for data transfer. The method further includes training a regression model, using the feature vectors for the plurality of federated query plans, to predict runtimes for executing federated queries using the variety of data sources as a federation engine. Some implementations use the trained regression model to determine a suitable federation engine for a given federated query.