| 摘要 |
An extensible database system is disclosed for storing data in a plurality of separate, lower-level databases. A top-level database is used to manipulate the data. The top-level database has a property dictionary file that stores the names of properties in the database system, along with references to their locations. An initial database system is created having a plurality of separate databases, each of which may store one or more fields, or properties. References to each of the initial databases are stored in the dictionary file. Thereafter, an added database may be used to add a property, or field, to the database system. The name of the added properties is stored in the dictionary file along with an address pointer to the memory location of the added database. To delete a properties, the reference to that properties is deleted from the property dictionary file and the properties data is removed from memory.
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