Apache ORC - the smallest, fastest columnar storage for Hadoop workloads

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  1. 2768f3b Add news for 1.7.6 by William Hyun · 2 days ago main
  2. 8f2b610 ORC-1253: Add Fedora 37 Docker test by William Hyun · 2 days ago
  3. 8510a4c ORC-1250: Bump mockito.version to 4.7.0 by dependabot[bot] · 4 days ago
  4. 68c68f8 ORC-1249: Move `site/_docs/releases.md` to `site/releases/index.md` by Dongjoon Hyun · 9 days ago
  5. f56fbaf ORC-1246: Revamp ORC website by William Hyun · 9 days ago

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.


  • Latest: Apache ORC releases
  • Maven Central: Maven Central
  • Downloads: Apache ORC downloads
  • Release tags: Apache ORC release tags
  • Plan: Apache ORC future release plan

The current build status:

  • Main branch main build status

Bug tracking: Apache Jira

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
  • tools - the c++ tools for reading and inspecting ORC files


  • Install java 1.8 or higher
  • Install maven 3.8.6 or higher
  • Install cmake

To build a release version with debug information:

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

To build a debug version:

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

To build a release version without debug information:

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

To build only the Java library:

% cd java
% ./mvnw package

To build only the C++ library:

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