Hadoop provides a table and storage management layer called HCatalog. With HCatalog users in Hive can use different data processing tools like- Pig, MapReduce, Hive, Streaming etc to read and write data on the grid.
With HCatalog we can read and write files in any format for which SerDe is available. Default options supported by HCatalog are: RCFile, CSV, JSON and SequenceFile.
In HCatalog we can see the data in a relational view.Read the full book at www.amazon.com