UDS/SQL can use all major BS2000 procedures to improve data security and availability.
UDS/SQL works smoothly in conjunction with the TimeFinder function of Symmetrix disk systems, enabling a BCV disk mirror to be established and split without interrupting database operation. Depending on the status of the database when it is split, the BCV creates either a consistent copy or an inconsistent "online" copy. The online copy must be brought up to a consistent status by means of log files.
The BS2000 function "Dual Recording by Volume" (DRV) can be used without any restrictions for UDS/SQL files. Should a system crash make it necessary to equalize the data stored on the DRV disks, this can be performed using UDS/SQL resources, i. e. DBH and utility routines, with greater precision and thus more quickly than with the BS2000 standard procedure (see section “Using data mirroring for UDS/SQL”).
The product HIPLEX AF (Highly Integrated Systems Complex) enables high availability applications to be implemented in an availability and load-sharing cluster of several BS2000 servers. This minimizes downtime by automatically detecting system failures and avoiding system restarts. The global transaction recovery facility and restart functions of UDS/SQL within the cluster ensure that no data is lost and no inconsistencies occur if a restart is performed on another computer.
A database backup can be created using BS2000 facilities, usually with the BS2000 utilities HSMS and ARCHIVE. With both utilities, it is possible to create a so-called "online copy" of a database. This procedure saves the database during live operation. Generally, this online backup copy is inconsistent; it can be made consistent, parallel to normal database operation, by applying the ALOG files in offline mode.