| 摘要 |
<p>Information is extracted from a database using a computer-implemented method that involves a sequential chain of main calculations, in which a first main calculation (P1) operates a first selection item (S1) on a data set (R0) that represents the database to produce a first result (R1), and a second main calculation (P2) operates a second selection item (S2) on the first result (R1) to produce a second result (R2). The first and second results (R1, R2) are cached in computer memory (10) for re-use in subsequent iterations of the method, thereby reducing the need to execute the first and/or second main calculations (P1, P2) for extracting the information. The caching involves calculating a first selection identifier value (ID1) as a function of at least the first selection item (S1), and a second selection identifier value (ID3) as a function of at least the second selection item (S2) and the first result (R1), and storing the first selection identifier value (ID1) and the first result (R1), and the second selection identifier value (ID3) and the second result (R2), respectively, as associated objects in a data structure (12). Each of the identifier values are generated as a statistically unique digital fingerprint by a hash function (f). The re-use involves calculating the first and second selection identifier values (ID1, ID3) during a subsequent iteration and accessing the data structure (12) to potentially retrieve the first and/or second result (R1, R2).</p> |
