IMPALA-12926: Refactor BINARY type handling in the backend

Currently the STRING and BINARY types are not distinguished in most of
the backend. In contrast to the frontend, PrimitiveType::TYPE_BINARY is
not used there at all, TYPE_STRING being used instead. This is to ensure
that everything that works for STRING also works for BINARY. So far only
file readers and writers have had to handle them differently, and they
have access to ColumnDescriptors which contain AuxColumnType fields that
differentiate these two types.

However, only top-level columns have ColumnDescriptors. Adding support
for BINARYs within complex types (see IMPALA-11491 and IMPALA-12651)
necessitates adding type information about STRING vs BINARY to embedded
fields as well.

Using PrimitiveType::TYPE_BINARY would probably be the cleanest solution
but it would affect huge parts of the code as TYPE_BINARY would have to
be added to hundreds of switch statements and this would be error prone.

Instead, this change introduces a new field in ColumnType: 'is_binary',
which is true if the type is a BINARY and false otherwise. We keep using
TYPE_STRING as the PrimitiveType of the ColumnType for BINARYs. This way
full type information is present in ColumnType but code that does not
differentiate between STRING and BINARY will continue to work for
BINARY.

With this change, AuxColumnType is no longer needed and is removed.

See also IMPALA-5323 - https://gerrit.cloudera.org/#/c/18868/. This
change is a very similar implementation of the same refactoring, except
for the Kudu related parts.

Testing:
 - added an extra test in binary-type.test

Change-Id: Icedbad4e24a46e7731de11cc14218761d11fb86f
Reviewed-on: http://gerrit.cloudera.org:8080/21157
Reviewed-by: Impala Public Jenkins <impala-public-jenkins@cloudera.com>
Tested-by: Impala Public Jenkins <impala-public-jenkins@cloudera.com>
21 files changed
tree: 8121d8526784c303ec77d5b89786005e14f9b658
  1. .devcontainer/
  2. be/
  3. bin/
  4. cmake_modules/
  5. common/
  6. docker/
  7. docs/
  8. fe/
  9. infra/
  10. java/
  11. lib/
  12. package/
  13. security/
  14. shell/
  15. ssh_keys/
  16. testdata/
  17. tests/
  18. www/
  19. .clang-format
  20. .clang-tidy
  21. .gitattributes
  22. .gitignore
  23. buildall.sh
  24. CMakeLists.txt
  25. EXPORT_CONTROL.md
  26. LICENSE.txt
  27. LOGS.md
  28. NOTICE.txt
  29. README-build.md
  30. README.md
  31. setup.cfg
README.md

Welcome to Impala

Lightning-fast, distributed SQL queries for petabytes of data stored in open data and table formats.

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:

More about Impala

The fastest way to try out Impala is a quickstart Docker container. You can try out running queries and processing data sets in Impala on a single machine without installing dependencies. It can automatically load test data sets into Apache Kudu and Apache Parquet formats and you can start playing around with Apache Impala SQL within minutes.

To learn more about Impala as a user or administrator, or to try Impala, please visit the Impala homepage. Detailed documentation for administrators and users is available at Apache Impala documentation.

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. Impala supports x86_64 and has experimental support for arm64 (as of Impala 4.0). Impala Requirements contains more detailed information on the minimum CPU requirements.

Supported OS Distributions

Impala runs on Linux systems only. The supported distros are

  • Ubuntu 16.04/18.04
  • CentOS/RHEL 7/8

Other systems, e.g. SLES12, may also be supported but are not tested by the community.

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 Impala's developer documentation to get started.

Detailed build notes has some detailed information on the project layout and build.