spark-instrumented-optimizer/sql
Liang-Chi Hsieh c0297dedd8 [MINOR][PYSPARK][SQL][DOC] Fix rowsBetween doc in Window
## What changes were proposed in this pull request?

I suspect that the doc of `rowsBetween` methods in Scala and PySpark looks wrong.
Because:

```scala
scala> val df = Seq((1, "a"), (2, "a"), (3, "a"), (4, "a"), (5, "a"), (6, "a")).toDF("id", "category")
df: org.apache.spark.sql.DataFrame = [id: int, category: string]

scala> val byCategoryOrderedById = Window.partitionBy('category).orderBy('id).rowsBetween(-1, 2)
byCategoryOrderedById: org.apache.spark.sql.expressions.WindowSpec = org.apache.spark.sql.expressions.WindowSpec7f04de97

scala> df.withColumn("sum", sum('id) over byCategoryOrderedById).show()
+---+--------+---+
| id|category|sum|
+---+--------+---+
|  1|       a|  6|              # sum from index 0 to (0 + 2): 1 + 2 + 3 = 6
|  2|       a| 10|              # sum from index (1 - 1) to (1 + 2): 1 + 2 + 3 + 4 = 10
|  3|       a| 14|
|  4|       a| 18|
|  5|       a| 15|
|  6|       a| 11|
+---+--------+---+
```

So the frame (-1, 2) for row with index 5, as described in the doc, should range from index 4 to index 7.

## How was this patch tested?

N/A, just doc change.

Closes #24864 from viirya/window-spec-doc.

Authored-by: Liang-Chi Hsieh <viirya@gmail.com>
Signed-off-by: HyukjinKwon <gurwls223@apache.org>
2019-06-14 09:56:37 +09:00
..
catalyst [SPARK-27578][SQL] Support INTERVAL ... HOUR TO SECOND syntax 2019-06-13 10:12:55 -07:00
core [MINOR][PYSPARK][SQL][DOC] Fix rowsBetween doc in Window 2019-06-14 09:56:37 +09:00
hive [SPARK-27578][SQL] Support INTERVAL ... HOUR TO SECOND syntax 2019-06-13 10:12:55 -07:00
hive-thriftserver [SPARK-27899][SQL] Make HiveMetastoreClient.getTableObjectsByName available in ExternalCatalog/SessionCatalog API 2019-06-11 15:32:59 +08:00
create-docs.sh [MINOR][DOCS] Minor doc fixes related with doc build and uses script dir in SQL doc gen script 2017-08-26 13:56:24 +09:00
gen-sql-markdown.py [SPARK-27328][SQL] Add 'deprecated' in ExpressionDescription for extended usage and SQL doc 2019-04-09 13:49:42 +08:00
mkdocs.yml [SPARK-21485][SQL][DOCS] Spark SQL documentation generation for built-in functions 2017-07-26 09:38:51 -07:00
README.md [MINOR][DOC] Fix some typos and grammar issues 2018-04-06 13:37:08 +08:00

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 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.