| 摘要 |
PURPOSE:To protect data and display record contents before and after update to make debugging easy by recording all of access data of a read system and a write system of the transaction processing in a pseudo access log file. CONSTITUTION:In the processing of the first transaction T1, data is read out from an actual file 25 at the time of a read instruction is issued by a transaction processing part 12. This record data is recorded as a log 27 before update in a pseudo access log file 26 together with record number information. At the time of this data A1 is updated to data A2 and a write instruction is issued, it is written as a log 28 after update in the file 26. At the time of the read instruction to the same record is issued in the next transaction T2, data is read from the file 26 by retrieval of access log, and data A2 is recorded as the log 27 before update. At the time of the write instruction to data A3 to which data A2 is updated on a main storage is issued, it is recorded as the log 28 after update similarly.
|
