Xref: utzoo alt.folklore.computers:9137 comp.periphs:3403 Path: utzoo!utgpu!cs.utexas.edu!sun-barr!apple!usc!zaphod.mps.ohio-state.edu!pacific.mps.ohio-state.edu!linac!fnal.fnal.gov!yossie From: yossie@fnal.fnal.gov (Yossie Silverman) Newsgroups: alt.folklore.computers,comp.periphs Subject: Re: External Sorting Message-ID: Date: 30 Jan 91 00:41:32 GMT Sender: daemon@linac.fnal.gov Organization: Fermilab Lines: 30 References:<1991Jan28.031017.19886@comp.vuw.ac.nz> <467@rufus.UUCP> In article <467@rufus.UUCP> drake@drake.almaden.ibm.com writes: > It is very rare these days that tapes are used as work files for sort > (disk > sort-work files are typical), but both tapes and disks are commonly used > as > input and output files for sort, with disk sort-work files being > essential > for the processing to operate. > > No matter how fast, a main-memory sort routine is essentially unusable > for commercial data processing applications. > > > Sam Drake / IBM Almaden Research Center > Internet: drake@ibm.com BITNET: DRAKE at ALMADEN > Usenet: ...!uunet!ibmarc!drake Phone: (408) 927-1861 Does IBM still include a "READ BACKWARDS" instruction in their tape drives? This instruction, I am told (and it seems logical) is primarily for sort routines, where reading backwards on the tape could actually save some time. Of course the bytes come in reversed, but that just needs some extra code to deal with. - Yossie --- yossie@fnal.fnal.gov; yossie@fnccf.bitnet What did the Caspian Sea? - Saki