79b05481a2
## What changes were proposed in this pull request? This PR addresses warning messages in Java files reported at [lgtm.com](https://lgtm.com). [lgtm.com](https://lgtm.com) provides automated code review of Java/Python/JavaScript files for OSS projects. [Here](https://lgtm.com/projects/g/apache/spark/alerts/?mode=list&severity=warning) are warning messages regarding Apache Spark project. This PR addresses the following warnings: - Result of multiplication cast to wider type - Implicit narrowing conversion in compound assignment - Boxed variable is never null - Useless null check NOTE: `Potential input resource leak` looks false positive for now. ## How was this patch tested? Existing UTs Closes #23420 from kiszk/SPARK-26508. Authored-by: Kazuaki Ishizaki <ishizaki@jp.ibm.com> Signed-off-by: Sean Owen <sean.owen@databricks.com> |
||
---|---|---|
.. | ||
catalyst | ||
core | ||
hive | ||
hive-thriftserver | ||
create-docs.sh | ||
gen-sql-markdown.py | ||
mkdocs.yml | ||
README.md |
Spark SQL
This module provides support for executing relational queries expressed in either SQL or the DataFrame/Dataset API.
Spark SQL is broken up into four subprojects:
- Catalyst (sql/catalyst) - An implementation-agnostic framework for manipulating trees of relational operators and expressions.
- Execution (sql/core) - A query planner / execution engine for translating Catalyst's logical query plans into Spark RDDs. This component also includes a new public interface, SQLContext, that allows users to execute SQL or LINQ statements against existing RDDs and Parquet files.
- Hive Support (sql/hive) - Includes an extension of SQLContext called HiveContext that allows users to write queries using a subset of HiveQL and access data from a Hive Metastore using Hive SerDes. There are also wrappers that allow users to run queries that include Hive UDFs, UDAFs, and UDTFs.
- HiveServer and CLI support (sql/hive-thriftserver) - Includes support for the SQL CLI (bin/spark-sql) and a HiveServer2 (for JDBC/ODBC) compatible server.
Running sql/create-docs.sh
generates SQL documentation for built-in functions under sql/site
.