Method for making a data base available to a user program during data

Abstract

A method and apparatus for allowing a user program, which has provided a global transaction to a remote system, to continue operation after only a partial recovery, thereby significantly reducing the delay associated with a detected fault or failure. The local transaction steps may be recovered by the local system. For all global transaction steps in a 'ready' state, a data base management system may re-establish the data base locks and system environment variables associated therewith. Thereafter, the user programs may continue operation and may access the un-locked portion of the data base, including the portion associated with the local transactions. In the meantime, a transaction manager may determine the actual status of the global transaction steps by performing the necessary communications with the remote systems. Once the actual status of a particular global transaction step is determined by the transaction manager, the global transaction step may be recovered, and the corresponding data base locks may be released. As the transaction manager determines the actual state of the remaining global transaction steps, more of the data base may be released to the user programs. Eventually, the entire data base may be available to the user programs.