| 摘要 |
A method apparatus for retrieval of data from an index database is disclosed. Each address in an index memory corresponds to an attribute that may be possessed by one or more records in the index database. Index memory datawords located at each index memory address include a number of binary bits equal to the number of records in the index database. If a record possesses an attribute, the value of the bit at a position corresponding to the record's address in that attribute's index memory dataword will be a binary "1". Priority encoder circuitry is provided to locate the positions of each of the 1's in the index memory datawords so that all of the records in the index database that possess an attribute can be determined. Logic circuitry is provided to combine index memory datawords logically to form new datawords that can be used to identify records that possess either all of a plurality of selected attributes, or one or more of a plurality of selected attributes. This retrieval system employs parallel hardware circuitry to increase data retrieval speed.
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