| 发明名称 | Candidate key retrieving apparatus, candidate key retrieving method and tangible machine-readable medium thereof | ||
| 摘要 | A candidate key retrieving apparatus, a candidate key retrieving method and a tangible machine-readable medium thereof are provided. The candidate key retrieving apparatus comprises a storage unit and a microprocessor. The storage unit is configured to store a table recording a data amount of the table, a plurality of attributes, and a data distinct amount and a data type of each attribute. The microprocessor is configured to generate a candidate key according to the data amount, the distinct amounts and the data types. | ||
| 申请公布号 | US8762377(B2) | 申请公布日期 | 2014.06.24 |
| 申请号 | US200912627798 | 申请日期 | 2009.11.30 |
| 申请人 | Institute for Information Industry | 发明人 | Kuo Tei-Wei;Shih Chi-Sheng;Luoh Ren-Shan;Suei Pei-Lun;Kuo Che-Wei;Liang Min-Siong |
| 分类号 | G06F7/00;G06F17/30 | 主分类号 | G06F7/00 |
| 代理机构 | Skaar Ulbrich Macari, P.A. | 代理人 | Skaar Ulbrich Macari, P.A. |
| 主权项 | 1. A method for setting a candidate key for a table, the method being used in an apparatus comprising a microprocessor and a storage unit electrically connected to the microprocessor, the storage unit being configured to store the table, the table recording a data amount of the table, a plurality of attributes of the table, a data distinct amount of each attribute and a data type of each attribute, the method comprising the following steps of: (a) enabling the microprocessor to generate a first attribute combination according to the attributes and the data type of each attribute, wherein the first attribute combination comprises a plurality of selected attributes, each of the selected attributes is one of the attributes, each of the selected attributes corresponds to a representation bit amount, each of the representation bit amount being used to determine the data distinct amount of the corresponding attribute; (b1) enabling the microprocessor to calculate a product of the data distinct amount of the selected attributes; (b2) enabling the microprocessor to determine that a product of the data distinct amount of the selected attributes is greater than or equal to the data amount; (c) enabling the microprocessor to generate a determination result according to an attribute number of the selected attributes of the first attribute combination; and (d) enabling the microprocessor to set the first attribute combination as the candidate key of the table according to the determination result. | ||
| 地址 | Taipei TW | ||