commit | 2b012e5a7beb1b688839566522191a8489adb944 | [log] [tgz] |
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author | boroknagyz <boroknagyz@gmail.com> | Wed Jan 15 03:18:11 2020 +0100 |
committer | Gang Wu <gangwu@apache.org> | Wed Jan 15 10:18:11 2020 +0800 |
tree | d1ed26205f58ba8ed2205e4cef3e9c7418a2094b | |
parent | 028261ad6e26d8ae9f9483c8aeb76a85c7f1168b [diff] |
ORC-589: [C++] add checks about negative dictionary entry lengths The library used to have a check for negative dictionary entry lengths. However we don't have it on current master. It causes a problem because it will use a negative value (casted to unsigned) to allocate a DataBuffer. This commit adds the missing check. This fixes #468
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