Abstract: In a database management system (DBMS) or other data processing system or product that stores and processes information, a subset of the stored information is stored as annotated values. Each annotated value has a stored data value and an associated data reliability value, where the data reliability value is a member of a domain that includes at least three distinct data reliability values corresponding to at least three distinct data reliability classifications that can apply to the annotated values stored in the database. Typically, one of the data reliability classifications represents fully reliable data and at least two of the distinct data reliability classifications represent two distinct classifications of missing data or less than fully reliable data. A query executer or other data processing procedure executes queries requesting access to information stored in the database (or other data processing tasks).

Abstract: A database management system (DBMS) is modified to provide improved concurrent usage of database objects, particularly when the system is executing long lived transactions. A subset of the transactions access database objects using parameterized read and parameterized write access modes. Each transaction using a parameterized write mode of access for a database object specifies a write access mode, and a write access mode parameter, where the parameter indicates a data reliability classification. Each transaction using a parameterized read mode of access for a database object specifies a read access mode, and a read access mode parameter, where the parameter indicates one or more reliability classifications that are acceptable to the transaction. Whenever a transaction requests access to a specified database object, the DBMS generates a corresponding lock request for the object. If the lock request is a parameterized lock request, a corresponding parameterized lock request is generated.