a570ee866e
Expression substitution recreates cast expressions without considering the compatibility level introduced by IMPALA-10173. In unsafe mode, the recreation causes IllegalStateException. This change fixes this behavior by storing the compatibility level in each CastExpr, and reusing it when the expression substitution recreates the cast expression. For example: 'select "1", "1" union select 1, "1"' Also, Set operation's common type calculations did not distinguish compatibility levels for each column slot, if one column slot's common type was considered unsafe, every other slot was treated as unsafe. This change fixes this behavior by reinitializing the compatibility level for every column slot, enabling cases where one column slot contains unsafely casted constant values and another contains non-constant expressions with regular casts. These queries failed before this change with 'Unsafe implicit cast is prohibited for non-const expression' error. For example: 'select "1", 1 union select 1, int_col from unsafe_insert' Tests: - test cases added to insert-unsafe.test Change-Id: I39d13f177482f74ec39570118adab609444c6929 Reviewed-on: http://gerrit.cloudera.org:8080/20184 Reviewed-by: Impala Public Jenkins <impala-public-jenkins@cloudera.com> Tested-by: Impala Public Jenkins <impala-public-jenkins@cloudera.com>
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, Apache Kudu, Amazon S3, Azure Data Lake Storage, Apache Hadoop Ozone and more!
- Wide analytic SQL support, including window functions and subqueries.
- On-the-fly code generation using LLVM to generate lightning-fast code tailored specifically to each individual query.
- Support for the most commonly-used Hadoop file formats, including Apache Parquet and Apache ORC.
- Support for industry-standard security protocols, including Kerberos, LDAP and TLS.
- Apache-licensed, 100% open source.
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.