spark-instrumented-optimizer/sql
Reynold Xin b1d719e7c9 [SPARK-21273][SQL] Propagate logical plan stats using visitor pattern and mixin
## What changes were proposed in this pull request?
We currently implement statistics propagation directly in logical plan. Given we already have two different implementations, it'd make sense to actually decouple the two and add stats propagation using mixin. This would reduce the coupling between logical plan and statistics handling.

This can also be a powerful pattern in the future to add additional properties (e.g. constraints).

## How was this patch tested?
Should be covered by existing test cases.

Author: Reynold Xin <rxin@databricks.com>

Closes #18479 from rxin/stats-trait.
2017-06-30 21:10:23 -07:00
..
catalyst [SPARK-21273][SQL] Propagate logical plan stats using visitor pattern and mixin 2017-06-30 21:10:23 -07:00
core [SPARK-21273][SQL] Propagate logical plan stats using visitor pattern and mixin 2017-06-30 21:10:23 -07:00
hive [SPARK-21273][SQL] Propagate logical plan stats using visitor pattern and mixin 2017-06-30 21:10:23 -07:00
hive-thriftserver [SPARK-20345][SQL] Fix STS error handling logic on HiveSQLException 2017-06-12 14:05:03 -07:00
README.md [SPARK-16557][SQL] Remove stale doc in sql/README.md 2016-07-14 19:24:42 -07:00

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 allows 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.