| 摘要 |
The invention concerns a general-applicability data-base system (DBS) for the storage, retrieval and manipulation of scan data, i.e. arrays of any (fixed or variable) size and dimensions and of any basic type. The invention is characterized by the strict separation of the logical (conceptual) and physical levels in order to ensure data independence, i.e. the possibility of addressing scan data irrespective of their physical storage structure, coding or state of compression. Depending on the data format required by the application, the DBS undertakes, in transparent fashion, the required conversion and (de)compression, taking into consideration accessing- and transmission-optimization aspects. At the conceptual level, the explicit definition of array structures provides the DBS, via a data-definition language (DDL), with knowledge of the complete array semantics. An orthogonal enquiry language (DML) includes array-specific primitives as well as operators which can be combined in any way to formulate optimizable DML expressions and predicates. Standard functions make explicit format conversion possible. At the physical level, a memory architecture based on a combination of array tiling and a spatial access structure (geo-index) permits efficient access to arrays and sub-arrays as well as the distribution of arrays over several, in certain cases heterogeneous, storage media. The invention is suitable above all for scanning applications with high requirements on functionality, data volume, network capability and access time, in particular for distributed, open multi-media systems. |
