> because of how the datastructure is laid out. if you use mmap, instead > of lots of seeks, it will simply be lots of page faults instead.
Ok, right, however assuming the pages are in RAM it could/should be ok. Eg, in HBase we'd want to store the keys alongside the column family values, on disk. Loading the keys into heap with the values still on disk/system IO cache probably is non-optimal. On Thu, Jun 2, 2011 at 8:45 PM, Robert Muir <rcm...@gmail.com> wrote: > On Thu, Jun 2, 2011 at 11:39 PM, Jason Rutherglen > <jason.rutherg...@gmail.com> wrote: >>> MMAP changes nothing: as its not a sequential pattern.. and things like >>> asking for a term range would be extra bad. >> >> Why's that? If the associated pages are in the system IO cache it'd be fine. >> > > because of how the datastructure is laid out. if you use mmap, instead > of lots of seeks, it will simply be lots of page faults instead. > > --------------------------------------------------------------------- > To unsubscribe, e-mail: dev-unsubscr...@lucene.apache.org > For additional commands, e-mail: dev-h...@lucene.apache.org > > --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@lucene.apache.org For additional commands, e-mail: dev-h...@lucene.apache.org
