On Saturday 06 February 2010 06:03:30 Greg Smith wrote: > Andres Freund wrote: > > On 02/03/10 14:42, Robert Haas wrote: > >> Well, maybe we should start with a discussion of what kernel calls > >> you're aware of on different platforms and then we could try to put an > >> API around it. > > > > In linux there is sync_file_range. On newer Posixish systems one can > > emulate that with mmap() and msync() (in batches obviously). > > > > No idea about windows. > The effective_io_concurrency feature had proof of concept test programs > that worked using AIO, but actually following through on that > implementation would require a major restructuring of how the database > interacts with the OS in terms of reads and writes of blocks. It looks > to me like doing something similar to sync_file_range on Windows would > be similarly difficult. Looking a bit arround it seems one could achieve something approximediately similar to pg_prepare_fsync() by using CreateFileMapping && MapViewOfFile && FlushViewOfFile If I understand it correctly that will flush, but not wait. Unfortunately you cant event make it wait, so its not possible to implement sync_file_range or similar fully. Andres -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
