To store data in an insertion process, a process 1 that inserts data into a new block and a process 2 that inserts, within the block reserved, data into areas that became free when data was deleted are prepared. A switching event to switch from the process 1 to the process 2 is designated in advance. The occurrence of the designated event is checked while executing the process 1 in an insertion process, and if the designated event occurs, the insertion process executes the process 2. If during the execution of the process 2, areas that can be reused become depleted, the execution of the insertion process reverts back to the process 1. As a result, free areas resulting from deletions can be reused according to the switching event designated.

A method and article of manufacture, implementing the method, allocates space for a dataset. The dataset has an initial area and zero or more additional allocated areas to provide space for storing the dataset. The size of a new additional area is determined. The new additional area is associated with a new area number, and the size of the new additional area is based on the new area number. Additional space for the dataset is allocated based on the size of the new additional area.

Techniques are provided for allowing the reorganization and/or redefinition of data in a relational database with minimal or no downtime by allowing "online" reorganization/redefinition of the data. According to one aspect of the invention, an empty revised table is created in the same schema as the target table. The revised table is created with the attributes that are desired for the reorganization/redefinition of the target table. Triggers, constraints, grants and indexes that are associated with the target table are replicated for the revised table. The reorganization/redefinition is performed by using an underlying mechanism that involves using incrementally maintainable materialized views. According to one feature, the revised table is initialized and periodically synchronized with the target table. After the reorganization and/or redefinition is complete on the revised table, the revised table and the target table switch identities such that the revised table is now the target table and the target table becomes the revised table.

For manufacturing security documents, a plurality of security documents are printed on a sheet. The sheets are being processed in batches (15a, 15b). Each sheet carries a unique, machine readable identifier. During manufacturing, the batches are processed by several printing stations (10). At each printing station, the identifiers are read by a local computer (13) attributed to the printing station. The results are transferred upon request in data packets to a central data base (16). Each data packet contains the information for several sheets, which obviates the need to transfer the corresponding data in real time over the network. To increase security and decrease network dependence, each local computer is equipped with apparatus to check the processing status of a batch autonomously.

The invention is a reconcile system for providing data replication between a source system and a target system. The reconcile system includes a reconcile process that determines a recovery position for a failed or otherwise desynchronized target system, and purges queues of the reconcile system of stale transactions occurring before the recovery position, thereby ensuring synchronization between the source and target systems.