| 摘要 |
In a distributed system, such as a PBX, which uses a database for its operation, a master copy of the database having a first format is stored at a central node and cache copies of database portions but having a different format are stored at peripheral nodes. A change to the database is made to the master copy, is recorded in a change table corresponding to the affected database portion, and is sent to affected peripheral nodes. At initialization, a boot copy is made of each database portion by translating the database portion from the master database format to the cache copy format. Periodically thereafter, each boot copy is replaced with a new boot copy that reflects changes presently recorded in the corresponding change table. When the new boot copy is generated, the present change table contents are erased. When a peripheral node calls for a new cache copy (e.g., upon reboot), it is sent the corresponding boot copy and any changes presently recorded in the corresponding change table.
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