| 摘要 |
A solution is proposed for managing a database in a data-processing system. A corresponding method (600) comprises the steps of providing (606-675), for a set of virtual tables each one comprising a set of virtual columns each one of a data type, a polymorph table stored in the database and a mapping structure, the polymorph table comprising a discrimination column for storing an identifier of the virtual tables and a total number of polymorph columns of each data type equal to a maximum number of the virtual columns of the data type in the virtual tables, and the mapping structure storing mapping information mapping each virtual column to a corresponding one of the polymorph columns of the same data type, receiving (678) a virtual access request for accessing at least part of the virtual tables, the virtual access request being based on at least a selected one of the virtual columns of at least a selected one of the virtual tables, retrieving (681) selected mapping information mapping each selected virtual column to a selected one of the polymorph columns from the mapping structure, converting (684-687) the virtual access request into a polymorph access request for the polymorph table according to the identifier of said at least one selected virtual table and the selected mapping information, and accessing (690-699) the polymorph table according to the polymorph access request. |
