Patent attributes
Techniques are disclosed relating to database schemas. A computer system may receive a metadata document that describes an updated schema for a database that stores a plurality of records. The computer system may instantiate a set of processes to perform an upgrade routine to upgrade ones of the plurality of records to comply with the updated schema. While the set of processes are upgrading the records, the computer system may receive a request to perform an operation on one of the plurality of records. The computer system may detect that the record corresponds to an earlier schema version than a version of the updated schema of the metadata document and may upgrade the record to comply with that updated schema. After upgrading the record, the computer system may perform the requested operation on the record.