Google Git
Sign in
apache / impala / 0936e3296697aa63f07c0919629d0967b88474e6
commit0936e3296697aa63f07c0919629d0967b88474e6[log] [tgz]
authorAlex Behm <alex.behm@cloudera.com>Fri Oct 06 22:11:04 2017 -0700
committerImpala Public Jenkins <impala-public-jenkins@gerrit.cloudera.org>Tue Dec 12 22:20:18 2017 +0000
treea8a8e894b57b42a7e6f3aa21eab7b2f1405eabe2
parente57c77f095cbf1660b02d629f7b0cb6a92491e0e [diff]
IMPALA-5310: Part 2: Add SAMPLED_NDV() function.

Adds a new SAMPLED_NDV() aggregate function that is
intended to be used in COMPUTE STATS TABLESAMPLE.
This patch only adds the function itself. Integration
with COMPUTE STATS will come in a separate patch.

SAMPLED_NDV() estimates the number of distinct values (NDV)
based on a sample of data and the corresponding sampling rate.
The main idea is to collect several x/y data points where x is
the number of rows and y is the corresponding NDV estimate.
These data points are used to fit an objective function to the
data such that the true NDV can be extrapolated.
The aggregate function maintains a fixed number of HyperLogLog
intermediates to compute the x/y points.
Several objective functions are fit and the best-fit one is
used for extrapolation.

Adds the MPFIT C library to perform curve fitting:
https://www.physics.wisc.edu/~craigm/idl/cmpfit.html

The library is a C port from Fortran. Scipy uses the
Fortran version of the library for curve fitting.

Testing:
- added functional tests
- core/hdfs run passed

Change-Id: Ia51d56ee67ec6073e92f90bebb4005484138b820
Reviewed-on: http://gerrit.cloudera.org:8080/8569
Reviewed-by: Alex Behm <alex.behm@cloudera.com>
Tested-by: Impala Public Jenkins
19 files changed
tree: a8a8e894b57b42a7e6f3aa21eab7b2f1405eabe2
  1. be/
  2. bin/
  3. cmake_modules/
  4. common/
  5. docs/
  6. ext-data-source/
  7. fe/
  8. impala-parent/
  9. infra/
  10. shell/
  11. ssh_keys/
  12. testdata/
  13. tests/
  14. www/
  15. .clang-format
  16. .clang-tidy
  17. .gitignore
  18. buildall.sh
  19. CMakeLists.txt
  20. EXPORT_CONTROL.md
  21. LICENSE.txt
  22. LOGS.md
  23. NOTICE.txt
  24. README.md
README.md

Welcome to Impala

Lightning-fast, distributed SQL queries for petabytes of data stored in Apache Hadoop clusters.

Impala is a modern, massively-distributed, massively-parallel, C++ query engine that lets you analyze, transform and combine data from a variety of data sources:

  • Best of breed performance and scalability.
  • Support for data stored in HDFS, Apache HBase and Amazon S3.
  • Wide analytic SQL support, including window functions and subqueries.
  • On-the-fly code generation using LLVM to generate CPU-efficient code tailored specifically to each individual query.
  • Support for the most commonly-used Hadoop file formats, including the Apache Parquet project.
  • Apache-licensed, 100% open source.

More about Impala

To learn more about Impala as a business user, or to try Impala live or in a VM, please visit the Impala homepage.

If you are interested in contributing to Impala as a developer, or learning more about Impala's internals and architecture, visit the Impala wiki.

Supported Platforms

Impala only supports Linux at the moment.

Export Control Notice

This distribution uses cryptographic software and may be subject to export controls. Please refer to EXPORT_CONTROL.md for more information.

Build Instructions

See bin/bootstrap_build.sh.

Detailed Build Notes

Impala can be built with pre-built components, downloaded from S3, or can be built with an in-place toolchain located in the thirdparty directory (not recommended). The components needed to build Impala are Apache Hadoop, Hive, HBase, and Sentry. If you need to manually override the locations or versions of these components, you can do so through the environment variables and scripts listed below.

Scripts and directories
LocationPurpose
bin/impala-config.shThis script must be sourced to setup all environment variables properly to allow other scripts to work
bin/impala-config-local.shA script can be created in this location to set local overrides for any environment variables
bin/impala-config-branch.shA version of the above that can be checked into a branch for convenience.
bin/bootstrap_build.shA helper script to bootstrap some of the build requirements.
bin/bootstrap_development.shA helper script to bootstrap a developer environment. Please read it before using.
be/build/Impala build output goes here.
be/generated-sources/Thrift and other generated source will be found here.
Build Related Variables
Environment variableDefault valueDescription
IMPALA_HOMETop level Impala directory
IMPALA_TOOLCHAIN“${IMPALA_HOME}/toolchain”Native toolchain directory (for compilers, libraries, etc.)
SKIP_TOOLCHAIN_BOOTSTRAP“false”Skips downloading the toolchain any python dependencies if “true”
CDH_COMPONENTS_HOME“${IMPALA_HOME}/toolchain/cdh_components” OR “${IMPALA_HOME}/thirdparty” (if detected)If a thirdparty directory is present, components found here will override anything in IMPALA_TOOLCHAIN.
CDH_MAJOR_VERSION“5”Identifier used to uniqueify paths for potentially incompatible component builds.
IMPALA_CONFIG_SOURCED“1”Set by ${IMPALA_HOME}/bin/impala-config.sh (internal use)
JAVA_HOME“/usr/lib/jvm/${JAVA_VERSION}”Used to locate Java
JAVA_VERSION“java-7-oracle-amd64”Can override to set a local Java version.
JAVA“${JAVA_HOME}/bin/java”Java binary location.
CLASSPATHSee bin/set-classpath.sh for details.
PYTHONPATHWill be changed to include: “${IMPALA_HOME}/shell/gen-py” “${IMPALA_HOME}/testdata” “${THRIFT_HOME}/python/lib/python2.7/site-packages” “${HIVE_HOME}/lib/py” “${IMPALA_HOME}/shell/ext-py/prettytable-0.7.1/dist/prettytable-0.7.1” "${IMPALA_HOME}/shell/ext-py/sasl-0.1.1/dist/sasl-0.1.1-py2.7-linux-x "${IMPALA_HOME}/shell/ext-py/sqlparse-0.1.14/dist/sqlparse-0.1.14-py2
Source Directories for Impala
Environment variableDefault valueDescription
IMPALA_BE_DIR“${IMPALA_HOME}/be”Backend directory. Build output is also stored here.
IMPALA_FE_DIR“${IMPALA_HOME}/fe”Frontend directory
IMPALA_COMMON_DIR“${IMPALA_HOME}/common”Common code (thrift, function registry)
Various Compilation Settings
Environment variableDefault valueDescription
IMPALA_BUILD_THREADS“8” or set to number of processors by default.Used for make -j and distcc -j settings.
IMPALA_MAKE_FLAGS""Any extra settings to pass to make. Also used when copying udfs / udas into HDFS.
USE_SYSTEM_GCC“0”If set to any other value, directs cmake to not set GCC_ROOT, CMAKE_C_COMPILER, CMAKE_CXX_COMPILER, as well as setting TOOLCHAIN_LINK_FLAGS
IMPALA_CXX_COMPILER“default”Used by cmake (cmake_modules/toolchain and clang_toolchain.cmake) to select gcc / clang
USE_GOLD_LINKER“true”Directs backend cmake to use gold.
IS_OSX“false”(Experimental) currently only used to disable Kudu.
Dependencies
Environment variableDefault valueDescription
HADOOP_HOME“${CDH_COMPONENTS_HOME}/hadoop-${IMPALA_HADOOP_VERSION}/”Used to locate Hadoop
HADOOP_INCLUDE_DIR“${HADOOP_HOME}/include”For ‘hdfs.h’
HADOOP_LIB_DIR“${HADOOP_HOME}/lib”For ‘libhdfs.a’ or ‘libhdfs.so’
HIVE_HOME“${CDH_COMPONENTS_HOME}/{hive-${IMPALA_HIVE_VERSION}/”
HIVE_SRC_DIR“${HIVE_HOME}/src”Used to find Hive thrift files.
HBASE_HOME“${CDH_COMPONENTS_HOME}/hbase-${IMPALA_HBASE_VERSION}/”
SENTRY_HOME“${CDH_COMPONENTS_HOME}/sentry-${IMPALA_SENTRY_VERSION}/”Used to setup test data
THRIFT_HOME“${IMPALA_TOOLCHAIN}/thrift-${IMPALA_THRIFT_VERSION}”