Class Reference

java.lang.Object
org.apache.hadoop.hbase.io.Reference

@Private public class Reference extends Object
A reference to the top or bottom half of a store file where 'bottom' is the first half of the file containing the keys that sort lowest and 'top' is the second half of the file with keys that sort greater than those of the bottom half. The file referenced lives under a different region. References are made at region split time.

References work with a special half store file type. References know how to write out the reference format in the file system and are what is juggled when references are mixed in with direct store files. The half store file type is used reading the referred to file.

References to store files located over in some other region look like this in the file system 1278437856009925445.3323223323: i.e. an id followed by hash of the referenced region. Note, a region is itself not splittable if it has instances of store file references. References are cleaned up by compactions.