Apache Orc

Clone this repo:
  1. 14b818a HIVE-14310. ORC schema evolutions should not completely disable PPD by Owen O'Malley · 10 months ago master
  2. 90a0cf8 HIVE-14333. ORC schema evolution from float to double break predicate pushdown. by Owen O'Malley · 10 months ago
  3. 7ac867d Trying again with travis link. by Owen O'Malley · 10 months ago
  4. 870df55 Trying to improve the travis CI link. by Owen O'Malley · 10 months ago
  5. c1a504d HIVE-14214. ORC schema evolution and predicate push down do not work together. by Owen O'Malley · 10 months 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 for reading and writing and a C++ library for reading 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.

The current build status:

  • Apache ORC master master build status

Building

  • Install java 1.7 or higher
  • Install maven 3 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
% cmake .. -DCMAKE_BUILD_TYPE=DEBUG
% make package
% make test-out

To build a release version without debug information:

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

To build only the Java library:

% cd java
% mvn package

To build only the C++ library:

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