spark-instrumented-optimizer/sql
Andrew Ray e1a172c201 [SPARK-21100][SQL] Add summary method as alternative to describe that gives quartiles similar to Pandas
## What changes were proposed in this pull request?

Adds method `summary`  that allows user to specify which statistics and percentiles to calculate. By default it include the existing statistics from `describe` and quartiles (25th, 50th, and 75th percentiles) similar to Pandas. Also changes the implementation of `describe` to delegate to `summary`.

## How was this patch tested?

additional unit test

Author: Andrew Ray <ray.andrew@gmail.com>

Closes #18307 from aray/SPARK-21100.
2017-07-08 13:47:41 +08:00
..
catalyst [SPARK-21335][SQL] support un-aliased subquery 2017-07-07 20:04:30 +08:00
core [SPARK-21100][SQL] Add summary method as alternative to describe that gives quartiles similar to Pandas 2017-07-08 13:47:41 +08:00
hive [SPARK-20703][SQL][FOLLOW-UP] Associate metrics with data writes onto DataFrameWriter operations 2017-07-07 13:12:20 +08:00
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.