[TUHS] Re: Perkin-Elmer Sort/Merge II vs Unix sort(1)

It appears that Diomidis Spinellis <dds(a)aueb.gr> said: That's not a resaonable comparison. In the 1960s and 1970s computers spent more time doing sort/merge than anything else, perhaps than everything else. Computer manufacturers tried really hard to make sorting fast, with clever hacks like compiling the comparison rules into machine code so they don't have to be reinterpreted for each record, scheduling their own I/O to keep devices busy, and reading intermediate tapes backward so they didn't have to rewind between passes. They also handle really big files, tape files that span more than one tape reel or sometimes disk files that span more than one removable pack.. In that era a tape held about 150MB and a 3330 disk pack was about 100MB. If you had big files, you had to keep them on tape and that meant a lot of sorting and merging to do updates. Even on disk, databases were nothing like they are now and what would now be in a SQL database was more likely in sorted files that were rewritten periodically with changes merged in. The P-E sort is a mainframe sort. Compare it to this IBM DOS VS sort and you'll see many of the same features, I am sure not by coincidence. https://bitsavers.computerhistory.org/pdf/ibm/370/DOS_VS/SC33-4044-2_DOS_VS… The unix sort program is fine for what it does which is sorting toy sized files on small disks. There's nothing wrong with that, I still use it all the time, but other than the name it doesn't have much in common with mainframe sort/merge.