I am working on a project that uses `SQLite` for handling `data aggregation`. I have `multiple SQLite database` files that are **split up by time**. I am planning on using the `SQLite ATTACH DATABASE` feature so I can run a single query against all the databases.

Each database has the same indexes and same table names. I wanted to be able to **run the single query** that would pull records from all the databases and sum values and some basic stuff like that. Then **run an update** to **flag** those records as already processed.

The question is: Will `SQLite` parallel the the execution of these queries? Will it create one reader for each database? Will it know to skip some databases based on the query and the index that is there?