Path: utzoo!utgpu!watserv1!watmath!att!att!bu.edu!rpi!zaphod.mps.ohio-state.edu!usc!ucsd!pacbell.com!pacbell!rtech!ingres!ingres.com!jpk From: jpk@ingres.com (Jon Krueger) Newsgroups: comp.arch Subject: Re: Memory mapping persistant data (was: >32 bits) Message-ID: <1990Oct30.020755.19614@ingres.Ingres.COM> Date: 30 Oct 90 02:07:55 GMT References: Lines: 20 From article , by Chuck.Phillips@FtCollins.NCR.COM (Chuck.Phillips): > [mmap] for painless on-demand loading of data? I suspect a DB engine > under UNIX could see some significant performance improvement by > leveraging off mmap() et al instead of attempting to duplicate it. Engines that support formal data models, ad hoc queries, and atomic, serializable, permanent transactions have performance characteristics that are not typically bottlenecked on the simple costs of loading data from disk to memory. Or, mmap ain't gonna save you in the real world. Might help under certain circumstances: sparse addressing, large ratio of reads to writes, page size not far from data element size. -- Jon Not speaking for anyone but myself. -- Jon Krueger, jpk@ingres.com