Apache ORC

ORC is a self-describing type-aware columnar file format designed for Hadoop workloads. It is optimized for large streaming reads, but with integrated support for finding required rows quickly. Storing data in a columnar format lets the reader read, decompress, and process only the values that are required for the current query. Because ORC files are type-aware, the writer chooses the most appropriate encoding for the type and builds an internal index as the file is written. Predicate pushdown uses those indexes to determine which stripes in a file need to be read for a particular query and the row indexes can narrow the search to a particular set of 10,000 rows. ORC supports the complete set of types in Hive, including the complex types: structs, lists, maps, and unions.

ORC File Library

This project includes both a Java library and a C++ library for reading and writing the Optimized Row Columnar (ORC) file format. The C++ and Java libraries are completely independent of each other and will each read all versions of ORC files. But the C++ library only writes the original (Hive 0.11) version of ORC files, and will be extended in the future.

Releases:

Latest: <a href="http://orc.apache.org/releases">Apache ORC releases</a>
Maven Central: <a href="http://search.maven.org/#search%7Cga%7C1%7Cg%3A%22org.apache.orc%22"></a>
Downloads: <a href="http://orc.apache.org/downloads">Apache ORC downloads</a>

The current build status:

Main branch <a href="https://travis-ci.com/apache/orc/branches"> </a>
<a href="https://travis-ci.com/github/apache/orc/pull_requests">Pull Requests</a>

Bug tracking: <a href="http://orc.apache.org/bugs">Apache Jira</a>

The subdirectories are:

c++ - the c++ reader and writer
cmake_modules - the cmake modules
docker - docker scripts to build and test on various linuxes
examples - various ORC example files that are used to test compatibility
java - the java reader and writer
proto - the protocol buffer definition for the ORC metadata
site - the website and documentation
snap - the script to build snaps of the ORC tools
tools - the c++ tools for reading and inspecting ORC files

Building

Install java 1.8 or higher
Install maven 3 or higher
Install cmake

To build a release version with debug information:

shell

% mkdir build
% cd build
% cmake ..
% make package
% make test-out

To build a debug version:

shell

% mkdir build
% cd build
% cmake .. -DCMAKE_BUILD_TYPE=DEBUG
% make package
% make test-out

To build a release version without debug information:

shell

% mkdir build
% cd build
% cmake .. -DCMAKE_BUILD_TYPE=RELEASE
% make package
% make test-out

To build only the Java library:

shell

% cd java
% mvn package

To build only the C++ library:

shell

% mkdir build
% cd build
% cmake .. -DBUILD_JAVA=OFF
% make package
% make test-out