Re: Raw partitions / cooked files

>That is only true if the o/s provides *guaranteed* synced writes. We do >open all chunks with O_SYNC, but even still this is not 100% reliable across >all platforms. I advocate raw IO for OnLine, but I think there is an amount of paranoia in thinking that there is an implementation of Unix where the Kernel can't keep track of whether or not the physical IO behind a sync'ed write occurred. Since the log has integrity due to sync'ed writes, AND ALL COMMITTED TRANSACTIONS ARE RE-APPLIED at fast-recovery, where is the data loss if some modified data page is trapped in the Unix cache at failure. The before image page is available and that's all that matters. ________________ Kevin A. Closson, Senior Technical Support Engineer voice: (503)578-3072 World Wide Technical Support, Database Group FAX: (503)578-5453 Sequent Computer Systems 15450 SW Koll Pkwy (MS WIL1-502) UUCP: ..uunet!sequent!kevinc Beaverton, Oregon 97006-6063 internet: kevinc@sequent.com