| 摘要 |
A multi-model database management system (DBMS) presents to its users a variety of logical models, or views of stored data, using industry-standard interfaces, while the physical storage of data is managed in a manner that closely follows the data model. Databases are built from sets of records using the entity-relationship data model. Space is reserved in each owner record for a set pointer pointing to either a member record or a Dynamic Pointer Array (DPA) structure that relates the owner record to member records. The DPA itself contains set pointers to all of the related member records. Each member record, in turn, has a set pointer pointing back to a particular owner record, or, in certain instances, to another DPA. In such cases, the DPA contains set pointers pointing to all of the related owner records. The DBMS supports a variety of logical models including the relational model, and further supports a plurality of industry-standard Application Program Interfaces using SQL query access language.
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