| 摘要 |
A computer database method wherein the data is organized into atomic data sets and transactions are separated into projections which operate on only one atomic data set. Multiple transactions can thereby access the same atomic data set using an optimistic protocol. An atomic data set counter is incremented on initial access to an atomic data set by a projection, and a local copy of the accessed data item is created. The issued command is executed while adding the timestamp and data item to the appropriate read or write set of the projection. Upon final access to the atomic data set by the projection, the local copy of the accessed data items is validated by comparing the read and write set of the projection with the read and write sets of all other projections that have accessed the atomic data set. If other projections conflict with the validating projection, the validating projection is aborted and restarted. Upon valid completion of the projection the local copy is written to the atomic data set.
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