| 摘要 |
PURPOSE:To change a key in a high speed, by constituting a system so that logical file corresponding information corresponding to the key is changed when the key in an physical file is changed. CONSTITUTION:Data of the same format are stored in records 2 in a physical file 1. A goods code, for example, alpha which is a key of indexes exists commonly in logical files LF1 and LF2 out of logical files FL1, FL2-. Bit positions corresponding to logical files LF1 and LF2 are set to (1) in case of alpha, and a bit position corresponding to the logical file LF1 is set to (1) in case of beta and gamma, and a bit position corresponding to the logical file LF2 is set to (1) in case of delta. If indexes are generated in this manner, it is sufficiently for the maintenance processing for change and addition of the key if only corresponding bit positions of indexes are changed and added, and thus, the processing operation is made efficient. |
