Dear Wiki user,

You have subscribed to a wiki page or wiki category on "Hadoop Wiki" for change 
notification.

The following page has been changed by NitayJoffe:
http://wiki.apache.org/hadoop/Hbase/NewFileFormat

------------------------------------------------------------------------------
  
  !MapFiles can be configured to compress each key/value entry or compress 
based off a block size.  Blocks do not span key/values but break on entries.
  
- Hbase keys are made of key/column/timestamp.  Rows and columns are 
effectively binary.  Timestamp is a long.  The sort is not a straight-forward 
binary sort; it has its idiosyncrasies embodied in the particular Comparator 
passed creating the store file: e.g. The timestamps are in reverse order 
because we want to find the newest first.
+ Hbase keys are made of row/column/timestamp.  Rows and columns are 
effectively binary.  Timestamp is a long.  The sort is not a straight-forward 
binary sort; it has its idiosyncrasies embodied in the particular Comparator 
passed creating the store file: e.g. The timestamps are in reverse order 
because we want to find the newest first.
  
  Every hbase flush creates a new !MapFile in the file system and an 
accompanying SequenceFile of metadata, an 'info' file.  Metadata includes the 
id of the last edit added the !MapFile and if the store file is a 'reference' 
file -- more on this later (TODO) -- it also includes info on whats referred to.
  

Reply via email to