Nonvolatile method of semiconductor disk device for the memory database recovery

Abstract

AbstractTo accelerate database processing, advanced intelligent networks and on‐line transaction processing systems employ memory databases in which all databases reside in main memory. Nonvolatile methods for the semiconductor disk devices backing up the memory databases have been proposed for these systems. Specifically, the methods adopted were a nonvolatile method using directly connected batteries and a method to transfer the contents of the semiconductor disk device to a magnetic disk drive which is a nonvolatile medium. An examination of the required nonvolatile time and the database capacity clearly demonstrated the application ranges of these two techniques by evaluating the battery capacity and the amount of hardware. Consequently, for a database capacity from 512 MB to 2 GB, the required nonvolatile time is about 10 hours. In the semiconductor disk device for an advanced intelligent network, the nonvolatile method using directly connected batteries was shown to be effective. To effectively maintain the batteries, a method to automatically decide whether to replace the batteries was proposed. Finally, the prototype battery structure based on these results and the structure for a service control node in the advanced intelligent network incorporating this battery structure were illustrated. © 2001 Scripta Technica, Electron Comm Jpn Pt 1, 84(9): 42–53, 2001