ad60c6d9be
## What changes were proposed in this pull request?
Because a review is resolved during analysis when we create a dataset, the content of the view is determined when the dataset is created, not when it is evaluated. Now the explain result of a dataset is not correctly consistent with the collected result of it, because we use pre-analyzed logical plan of the dataset in explain command. The explain command will analyzed the logical plan passed in. So if a view is changed after the dataset was created, the plans shown by explain command aren't the same with the plan of the dataset.
```scala
scala> spark.range(10).createOrReplaceTempView("test")
scala> spark.range(5).createOrReplaceTempView("test2")
scala> spark.sql("select * from test").createOrReplaceTempView("tmp001")
scala> val df = spark.sql("select * from tmp001")
scala> spark.sql("select * from test2").createOrReplaceTempView("tmp001")
scala> df.show
+---+
| id|
+---+
| 0|
| 1|
| 2|
| 3|
| 4|
| 5|
| 6|
| 7|
| 8|
| 9|
+---+
scala> df.explain
```
Before:
```scala
== Physical Plan ==
*(1) Range (0, 5, step=1, splits=12)
```
After:
```scala
== Physical Plan ==
*(1) Range (0, 10, step=1, splits=12)
```
## How was this patch tested?
Manually test and unit test.
Closes #24415 from viirya/SPARK-27439.
Authored-by: Liang-Chi Hsieh <viirya@gmail.com>
Signed-off-by: Dongjoon Hyun <dhyun@apple.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.