Ryan, Thanks for your quick response.
Since HFiles can not be modified in the HDFS once written, I guess the write buffer take all this modified data block in buffer and overwrite the whole HDFS data block corresponding to the HFile changed before. I need reread the bigTable papers, always has questions... Thanks On Sat, Aug 28, 2010 at 11:58 PM, Ryan Rawson <[email protected]> wrote: > Hfiles are write once read many. Once written they cannot be modified so > there is way to move things around. > > Hbase deals with this by having a robust write buffer and writing large > files. > > For more architectural details check out the bigtable paper. > > On Aug 28, 2010 8:32 PM, "zhixuan zhu" <[email protected]> wrote: > > hey guys, > > > > I am studying the HFiles now and have a couple of questions. > > > > The keys in the HFiles are sorted. So when a key is inserted into a data > > block which is full and the key is smaller than the greatest key in this > > data block and greater than the smallest key in this data block. In this > > case, does the data block need reorganize? say keys greater than the > > inserted keys into next data block?. > > > > And if a value for a key needs update, how is this achieved in HFIle? > > > > Appreciate your time for answering my questions! > > > > Thanks > > > > Tim Zhu >
