Efficient data processing for schema changes

A method for processing database data, comprising:

• receiving a query for the database data comprising a date range and a data selection criterion;
• determining, using a processor, a set of fields of the database data corresponding to a schema of the database data at a most recent date of the date range;
• determining a subset of the set of fields of the database data specified by the data selection criterion;
• determining a set of transformations, wherein each transformation of the set of transformations corresponds to a field of the subset and a sub-range of the date range, comprising:
• determining whether a schema update transformation applies between a next date and a target date, wherein the next date includes a first date of the date range, and wherein the target date includes the end date of the date range;
• and
• in response to a determination that the schema update transformation does not apply between the next date and the target date, omitting to include the schema update transformation in the set of transformations;
• collecting data from the database data using one or more data access rules associated with the subset of the set of fields and the data range to obtain collected database data;
• transforming the collected database data using the set of transformations to determine transformed database data, wherein the transformed database data comprises a consistent schema corresponding to the schema of the database data at the most recent date of the date range;
• and
• selecting data from the transformed database data using the data selection criterion to determine a query response.

A computer program product for processing database data, the computer program product being embodied in a non-transitory computer readable storage medium and comprising computer instructions for:

• receiving a query for the database data comprising a date range and a data selection criterion;
• determining a set of fields of the database data corresponding to a schema of the database data at a most recent date of the date range;
• determining a subset of the set of fields of the database data specified by the data selection criterion;
• determining a set of transformations, wherein each transformation of the set of transformations corresponds to a field of the subset and a sub-range of the date range, comprising:
• determining whether a schema update transformation applies between a next date and a target date, wherein the next date includes a first date of the date range, and wherein the target date includes the end date of the date range;
• and
• in response to a determination that the schema update transformation does not apply between the next date and the target date, omitting to include the schema update transformation in the set of transformations;
• collecting data from the database data using one or more data access rules associated with the subset of the set of fields and the data range to obtain collected database data;
• transforming the collected database data using the set of transformations to determine transformed database data, wherein the transformed database data comprises a consistent schema corresponding to the schema of the database data at the most recent date of the date range;
• and
• selecting data from the transformed database data using the data selection criterion to determine a query response.