Hive DDL

ORC is well integrated into Hive, so storing your istari table as ORC is done by adding “STORED AS ORC”.

CREATE TABLE istari ( name STRING, color STRING ) STORED AS ORC;

To modify a table so that new partitions of the istari table are stored as ORC files:

ALTER TABLE istari SET FILEFORMAT ORC;

As of Hive 0.14, users can request an efficient merge of small ORC files together by issuing a CONCATENATE command on their table or partition. The files will be merged at the stripe level without reserialization.

ALTER TABLE istari [PARTITION partition_spec] CONCATENATE;

To get information about an ORC file, use the orcfiledump command.

% hive --orcfiledump <path_to_file>

As of Hive 1.1, to display the data in the ORC file, use:

% hive --orcfiledump -d <path_to_file>