> > - Asynchronous File I/O > > It is not really asynchronous as it waits for the completion of every > single IO > request.
True, but it allows the storage controller to decide the best order in which to perform the operations... > Also, note, it completely disables file system caching. It kills write > performance Really? I could see a benefit for writing several pages, which are of the same 'priority/level' in the "carefully order writes", through a single operation for any storage device. Fewer calls would improve performance. Separately, I seem to recall that the feature was completed and released in a IB 6.5+ release. > There is no UNIX part of it, btw. Unix/Linux... Smm-*nix!! Don't you know, Windows is the only platform that matters! > > - Defer Header Page Write (i.e. reduce the number of times that the > > header page is written to disk) > > This is most mature piece of code and i'm going to use it as a base for the > our implementation. It have no support for CS and, of course, it must be > tested very carefully. Interesting that you want to continue with it... Although, I see the benefits of avoiding the "sun level hotspot" that is the DB Header page write operations. I don't see how database integrity can be maintained if the header page changes are not persisted to disk immediately -- aside from an MPI based multi-node cluster where pages changes are sent to other nodes (as witnesses for safekeeping)*. Sean * This approach could actually provide several possible benefits... Even over 10GBs TCP connection (w/properly configured MTU) MPI latencies (for 4KB messages) are < 250 micro-seconds (us) whereas SSD/PCIe SSDs latencies are 10-5 (ms). Using 10GBs RDMA, latencies are < 100 micro-seconds (us). Using latest RDMA NICs, latencies are < 15 micro-seconds (us). ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot Firebird-Devel mailing list, web interface at https://lists.sourceforge.net/lists/listinfo/firebird-devel
