| 摘要 |
A database management system for preventing deadlocks from occurring during control while securing execution rights and securing locks, for efficiently operating the application program in a multi-thread environment, and also for limiting the amount of time wasted in standby during synchronous processing for maintenance of execution rights. In this system, once the execution rights to the threads corresponding to a cache resource have been secured, a lock is secured on a transaction operated on a thread secured by an exclusive controller for a resource of a database corresponding to a resource in the cache resource. When a lock cannot be secured for a particular transaction, the exclusive controller informs the synchronization processor of a lock failure the previously secured execution right is automatically discarded so that execution rights to other threads in standby can be secured. In this way deadlocks regarding to control of thread operation are prevented from occurring. Furthermore, execution rights are synchronously processed for each group of exclusive control process data of the lock, and data groups independent of each other in exclusive control are synchronously processed without a standby state.
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