Abstract: Storage level query processing may be implemented for processing database queries. Nodes that can access a database may perform parallel processing for at least a portion of a database query. An indication may be received that specifies parallel processing for the database query. The nodes can then be caused to perform the portion of the query as part of providing a result in response to the database query instead of a node, such as a query engine node, that received the database query.

Abstract: Online reordering for database table columns may allow a user to reorder the columns of a database table without taking the database offline. A mapping between different column orders for a database table may be generated and stored in response to a request to reorder columns in a database table. When a portion of the database table is accessed, the columns of the database table in the accessed portion of the database table may be reordered to perform the access request.

Abstract: A data store may implement on-demand data schema modifications. Request to change a schema for a data set in a data store may be received and a description of the change recorded as part of a schema history for the data set. The request to change the schema may then be acknowledged. When access requests directed to the data set are received at the data store, the schema history for the data set may be evaluated. If the schema history indicates that data that is to be accessed in order to service the data store needs to include one or more changes in the schema history, then a version of the schema that includes the one or more changes may be applied to the data.