Caching results for sub-queries to different data store locations

A method, comprising:

• responsive to a first query to a database received at a first query engine, storing results of one or more sub-queries performed by different respective query engines to obtain the results for the first query from different storage locations in a data store for the database;
• and
• responsive to a second query to the database received at the first query engine,
• obtaining, by the first query engine, the stored results directly instead of causing the different respective query engines to perform the one or more sub-queries to obtain the stored results;
• and
• including, by the first query engine, the stored results in a final result for the second query.

A non-transitory, computer-readable storage medium, storing program instructions that when executed by one or more computing devices cause the one or more computing devices to implement:

• responsive to a first query to a database received at a first query engine:
• causing, by the first query engine, different respective query engines to perform one or more sub-queries to obtain respective results for the one or more sub-queries from different storage locations in a data store for the database to include a final result returned for the first query;
• storing, by the first query engine, the results of one or more sub-queries;
• and
• responsive to a second query to the database received at the first query engine,
• obtaining, by the first query engine, the stored results directly instead of causing the different respective query engines to perform the one or more sub-queries to obtain the stored results;
• and
• including, by the first query engine, the stored results in a final result for the second query.