Jacek Laskowski created SPARK-25278:
---------------------------------------
Summary: Number of output rows metric of union of views is
multiplied by their occurrences
Key: SPARK-25278
URL: https://issues.apache.org/jira/browse/SPARK-25278
Project: Spark
Issue Type: Bug
Components: SQL
Affects Versions: 2.3.1
Reporter: Jacek Laskowski
Attachments: union-2-views.png, union-3-views.png
When you use a view in a union multiple times (self-union), the {{number of
output rows}} metric seems to be the correct {{number of output rows}}
multiplied by the occurrences of the view, e.g.
{code:java}
scala> spark.version
res0: String = 2.3.1
val name = "demo_view"
sql(s"CREATE OR REPLACE VIEW $name AS VALUES 1,2")
assert(spark.catalog.tableExists(name))
val view = spark.table(name)
assert(view.count == 2)
view.union(view).show // gives 4 for every view, but should be 2
view.union(view).union(view).show // gives 6{code}
I think it's because {{View}} logical operator is a {{MultiInstanceRelation}}
(and think other {{MultiInstanceRelation}}s may also be affected).
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
