Critical Analysis of Artificial Intelligence In Reference to Artificial Neural Network |
An ideal disk format would replicate exactly what isin memory. When this is done on a virtual-memory machine with flexible pagingfacilities, it is not necessary to read or write the entire design file atonce. Instead, the file is "attached" to virtual memory bydesignating the disk blocks of the file to be the paging space for the designprogram. Initially these memory pages are all "swapped out" but, asdesign activity references new data, the appropriate disk blocks are paged in.Changes to the design manipulate the disk file in only those placescorresponding to the modified memory. Allocation of more memory for a largerdesign automatically extends the size of the disk file. Of course, writing thedesign simply involves updating the changed pages. This scheme requires thesmallest amount of disk I/O since it accesses only what it needs and does notrequire a separate paging area on disk.