| 摘要 |
A database enables versioning for objects stored in the database via a“snapshot”operation. In one implementation, a device performs a snapshot operation in which a snapshot object, representing a logical view of database objects at a time at which the snapshot operation is performed, is created and stored in the database. In response to a request to store a modified version of a database object, the modified version of the database object is written to replace the previous version of the database object when the database object was last modified after the most recent snapshot operation. Further, in response to the request to store the modified version of the database object, the modified version of the database object is inserted in the database when the previous version of the database object was last modified before the most recent snapshot operation. |
