US Patent 11537568 Efficient data processing for schema changes

A system for processing database data includes an interface and a processor. The interface is configured to receive a query for the database data comprising a date range and a data selection criterion. The processor is configured to determine a set of fields of the database data corresponding to a most recent date of the date range; determine a subset of the set of fields of the database data specified by the data selection criterion; determine a set of transformations, where each transformation of the set of transformations corresponds to a field of the subset and a sub-range of the date range; transform the database data to determine transformed database data using the set of transformations; and select data from the transformed database data using the data selection criterion to determine a query response.