[Lucene-hadoop Wiki] Update of "Hbase" by JimKellerman

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The following page has been changed by JimKellerman:
http://wiki.apache.org/lucene-hadoop/Hbase

New page:
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= Hbase - Bigtable-like structured storage for Hadoop HDFS =

== Background ==

Google's [http://labs.google.com/papers/bigtable.html Bigtable],
a distributed storage system for structured data, is a very effective 
mechanism for storing very large amounts of data in a distributed
environment.
 
Just as Bigtable leverages the distributed data storage provided
by the [http://labs.google.com/papers/gfs.html Google File System],
Hbase will provide Bigtable-like capabilities on top of Hadoop.

Data is organized into tables, rows and columns, but a query language
like SQL is not supported. Instead, an Iterator-like interface is available
for scanning through a row range (and of course there is an ability to
retrieve a column value for a specific key).

Any particular column may have multiple values for the same row key.
A secondary key can be provided to select a particular value or an
Iterator can be set up to scan through the key-value pairs for that column 
given a specific row key.

== Rationale ==

Both Google's GFS and Hadoop's HDFS provide a mechanism to
reliably store large amounts of data. However, there is not really a 
mechanism for organizing the data and accessing only the parts that
are of interest to a particular application.

Bigtable (and Hbase) provide a means for organizing and efficiently
accessing these large data sets.

= Project Links =

Self:HbaseArchitecture - architecture - a work in progress.

== Initial Contributors ==

  * JimKellerman [[MailTo(jim AT SPAMFREE powerset DOT com)]]
  * Doug Judd [[MailTo(doug AT SPAMFREE zvents DOT com)]]
  * Ivan Small [[MailTo(ivan AT SPAMFREE blueseaturtle DOT com)]]