Nice CPUs (was: Virtual vs Physical memory (was Re: Designing around a 6502 ))

On Wed, 12 Feb 2003, Jeffrey Sharp wrote: I'd tend to guess that the 1MB fields probably come from the storage device holding the database... Unless you're assuming that the database is stored in someone's brain, and that they're toggling in those 1MB fields on the console switches. The original problem has the given of there being a database. I think we can safely assume that there's at least one "table" in the database, and that within this table there is more than one record--otherwise the excercise of sorting it would be rather silly--and that those records have at least one field of 1MB in size. The original problem implied there were more though, which would make the task more challenging. The other given is that you've a machine with 1MB of RAM. So... it very logically /follows/ that this database has to live somewhere, and it has to live somewhere that's not in RAM. Whether one assumes it's on a floppy disk, a hard disk, tape drive, paper tape, punch cards, or that it's being interactively toggled in via the console switches--the process being suggested for sorting it still holds, albeit with varying degrees of performance. Hans' assumption of it being disk I/O based is the most sensible of those options, but the general approach of his solution is valid with any of the other alternatives. And if you assume you don't have some sort of I/O channel for accessing this database, the problem most assuredly won't be with not having enough RAM! Actually, there are two other options: (1) the database is entirely in RAM, it has one table, with one record, with one field of precisely 1MB in size, or (2) the database has zero records. In either of those cases, you don't even need to write a sorting program since the tables are already sorted. -brian.