Abstract: A computing system associates time series data with data base changes, received from concurrent processes, that are recorded in an activity log by defining a data base table to include a column in which a system clock time stamp value can be recorded when initializing a new copy of the data. Initialization can be set to occur automatically at periodic intervals or whenever a fresh copy of a set of data records is requested by a system process. The writing of the time stamp data associates a time value with the copy initialization activity and makes time series data available to processes that otherwise would have no time knowledge. The prior user-defined data base does not have to be modified to utilize the time stamp feature because a new, system-defined table is used.

Abstract: A computer processing system that receives sequences of changes to a data base and records them into an activity log for later retrieval also maintains a consistent change data table that contains sufficient change information for each of the changes to the data base such that the changes can be propagated through multiple copies of the data base by consulting the consistent change data table. The consistent change data includes information sufficient to permit reconstruction of the data base to reflect the condition of the data base at any moment of time in the activity log. Because the consistent change data is complete, it permits producing multi-generational copies of data base tables for replication from one copy level to any other subsequent level, or iteration, of copy.

Abstract: A computer processing system that receives sequences of changes to a data base and records them into an activity log for later retrieval also maintains a consistent change data table that contains sufficient change information for each of the changes to the data base such that the changes can be propagated through multiple copies of the data base by consulting the consistent change data table. The consistent change data includes information sufficient to permit reconstruction of the data base to reflect the condition of the data base at any moment of time in the activity log. Because the consistent change data is complete, it permits producing multi-generational copies of data base tables for replication from one copy level to any other subsequent level, or iteration, of copy.

Abstract: A relational data base management system permits users to specify copy operations without being burdened with specifying details of structure, copy refresh algorithm, and the like. The attributes a user must specify when requesting snapshot copies is reduced by defining data structures with attributes such that specifying the name of a table, whether a user data table or snapshot, specifies the copying scheme that will be used. Any ambiguity is resolved by interactively querying the user. When a user initially defines, or registers, a source table, the user specifies a set of predefined attributes, including table structure and completeness. When a user later requests a snapshot copy, the system automatically determines the nature of the copy operation to be performed by matching the table name with its registered attributes.