HFile uses in memory indexes to only need 1 seek to access data. How is this only "decent" ?
As for memory mapped files, given that HDFS files are not local, we can't mmap() them. However HBase does block caching in memory to reduce the trips to HDFS. -ryan On Mon, Apr 26, 2010 at 11:33 AM, Geoff Hendrey <ghend...@decarta.com> wrote: > Hi, > > Any pointers on how to optimize hbase for random access? My > understanding is that HFile is decent at random access. Why doesn't it > use memory mapped I/O? (my reading on it indicated it uses "something > like NIO"). I'd like my entire table to be distributed across region > servers, so that random reads are quickly served by a region server > without having to transfer a block from HDFS. Is this the right > approach? I would have thought that some sort of memory-mapped region > file would be perfect for this. Anyway, just looking to understand the > best practice(s). > > > -geoff > > >
