commit | 7bec5e06f7da40074f206ef2c8790368f3d8d889 | [log] [tgz] |
---|---|---|
author | Piotr Findeisen <piotr.findeisen@gmail.com> | Thu Aug 13 22:21:34 2020 +0200 |
committer | Owen O'Malley <omalley@apache.org> | Fri Aug 21 10:51:17 2020 -0700 |
tree | 1d0932b0de90db18f8f034c6a9f97bf5847bd2c1 | |
parent | 0268b4fd1f19c9076fe94eb19194df3e0a9dc5cd [diff] |
Fix Julian/Gregorian cutoff in a comment Fixes #538 Signed-off-by: Owen O'Malley <omalley@apache.org>
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.
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:
The current build status:
Bug tracking: Apache Jira
The subdirectories are:
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