Reading Records from a Sequence File

[maha]

Hello Everyone,

        As far as I know, when my java program opens a sequence file for a map 
calculations, from hdfs. Using SequenceFile.Reader(key,value) will actually 
read the file in dfs.block.size then grabes record-by-record from memory.

  Is that right? 

.. I tried a simple program with input about 6 MB, but the memory allocated was 
13 MB!  .. which might be a fragmentation problem, but I doubt it.

 Thank you,
 Maha