HBase

HBase is a key-valued row/column store modeled on Google’s Bigtable providing Bigtable-like capabilities for Hadoop. That is, it provides a fault-tolerant way of storing large quantities of sparse data (small amounts of information caught within a large collection of empty or unimportant data, such as finding the 50 largest items in a group of 2 billion records, or finding the non-zero items representing less than 0.1% of a huge collection).

Unlike relational and traditional databases, HBase does not support SQL scripting; instead the equivalent is written in Java, employing similarity with a MapReduce application.

In the parlance of Eric Brewer's CAP Theorem, HBase is a CP type system.

Data model

Data Storage

Querying

Retrieve a cell:

Cell cell = table.getRow(“enclosure1”).getColumn(“animal:type”).getValue();

Retrieve a row:

RowResult row = table.getRow( “enclosure1” );

Scan through a range of rows:

Scanner s = table.getScanner( new String[] { “animal:type” } );