Skip to content

Conversation

@cloud-fan
Copy link
Contributor

What changes were proposed in this pull request?

In #22732 , we tried our best to keep the behavior of Scala UDF unchanged in Spark 2.4.

However, since Spark 3.0, Scala 2.12 is the default. The trick that was used to keep the behavior unchanged doesn't work with Scala 2.12.

This PR proposes to remove the Scala 2.11 hack, as it's not useful.

How was this patch tested?

existing tests.


- Since Spark 3.0, JSON datasource and JSON function `schema_of_json` infer TimestampType from string values if they match to the pattern defined by the JSON option `timestampFormat`. Set JSON option `inferTimestamp` to `false` to disable such type inferring.

- In Spark version 2.4 and earlier, if `org.apache.spark.sql.functions.udf(Any, DataType)` gets a Scala closure with primitive-type argument, the returned UDF will return null if the input values is null. Since Spark 3.0, the UDF will return the default value of the Java type if the input value is null. For example, `val f = udf((x: Int) => x, IntegerType)`, `f($"x")` will return null in Spark 2.4 and earlier if column `x` is null, and return 0 in Spark 3.0.
Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

this migration guide should have been added when we switch to Scala 2.12.

Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

should this say this is because of Scala 2.12?

@cloud-fan
Copy link
Contributor Author

@HyukjinKwon
Copy link
Member

Yea, I agree with this change.

@SparkQA
Copy link

SparkQA commented Jan 9, 2019

Test build #100962 has finished for PR 23498 at commit d66a9c9.

  • This patch passes all tests.
  • This patch merges cleanly.
  • This patch adds no public classes.

@SparkQA
Copy link

SparkQA commented Jan 10, 2019

Test build #101014 has finished for PR 23498 at commit e0053af.

  • This patch fails Spark unit tests.
  • This patch merges cleanly.
  • This patch adds no public classes.

@cloud-fan
Copy link
Contributor Author

retest this please

@SparkQA
Copy link

SparkQA commented Jan 10, 2019

Test build #101015 has finished for PR 23498 at commit e0053af.

  • This patch fails Spark unit tests.
  • This patch merges cleanly.
  • This patch adds no public classes.

@SparkQA
Copy link

SparkQA commented Jan 10, 2019

Test build #4501 has finished for PR 23498 at commit e0053af.

  • This patch fails Spark unit tests.
  • This patch merges cleanly.
  • This patch adds no public classes.

@HyukjinKwon
Copy link
Member

retest this please

@SparkQA
Copy link

SparkQA commented Jan 11, 2019

Test build #101046 has finished for PR 23498 at commit e0053af.

  • This patch passes all tests.
  • This patch merges cleanly.
  • This patch adds no public classes.

@cloud-fan
Copy link
Contributor Author

thanks, merging to master!

@cloud-fan cloud-fan closed this in 1f1d98c Jan 11, 2019
jackylee-ch pushed a commit to jackylee-ch/spark that referenced this pull request Feb 18, 2019
## What changes were proposed in this pull request?

In apache#22732 , we tried our best to keep the behavior of Scala UDF unchanged in Spark 2.4.

However, since Spark 3.0, Scala 2.12 is the default. The trick that was used to keep the behavior unchanged doesn't work with Scala 2.12.

This PR proposes to remove the Scala 2.11 hack, as it's not useful.

## How was this patch tested?

existing tests.

Closes apache#23498 from cloud-fan/udf.

Authored-by: Wenchen Fan <[email protected]>
Signed-off-by: Wenchen Fan <[email protected]>
cloud-fan pushed a commit that referenced this pull request Feb 21, 2020
…F by default

### What changes were proposed in this pull request?

This PR proposes to throw exception by default when user use untyped UDF(a.k.a `org.apache.spark.sql.functions.udf(AnyRef, DataType)`).

And user could still use it by setting `spark.sql.legacy.useUnTypedUdf.enabled` to `true`.

### Why are the changes needed?

According to #23498, since Spark 3.0, the untyped UDF will return the default value of the Java type if the input value is null. For example, `val f = udf((x: Int) => x, IntegerType)`, `f($"x")` will  return 0 in Spark 3.0 but null in Spark 2.4. And the behavior change is introduced due to Spark3.0 is built with Scala 2.12 by default.

As a result, this might change data silently and may cause correctness issue if user still expect `null` in some cases. Thus, we'd better to encourage user to use typed UDF to avoid this problem.

### Does this PR introduce any user-facing change?

Yeah. User will hit exception now when use untyped UDF.

### How was this patch tested?

Added test and updated some tests.

Closes #27488 from Ngone51/spark_26580_followup.

Lead-authored-by: yi.wu <[email protected]>
Co-authored-by: wuyi <[email protected]>
Signed-off-by: Wenchen Fan <[email protected]>
cloud-fan pushed a commit that referenced this pull request Feb 21, 2020
…F by default

### What changes were proposed in this pull request?

This PR proposes to throw exception by default when user use untyped UDF(a.k.a `org.apache.spark.sql.functions.udf(AnyRef, DataType)`).

And user could still use it by setting `spark.sql.legacy.useUnTypedUdf.enabled` to `true`.

### Why are the changes needed?

According to #23498, since Spark 3.0, the untyped UDF will return the default value of the Java type if the input value is null. For example, `val f = udf((x: Int) => x, IntegerType)`, `f($"x")` will  return 0 in Spark 3.0 but null in Spark 2.4. And the behavior change is introduced due to Spark3.0 is built with Scala 2.12 by default.

As a result, this might change data silently and may cause correctness issue if user still expect `null` in some cases. Thus, we'd better to encourage user to use typed UDF to avoid this problem.

### Does this PR introduce any user-facing change?

Yeah. User will hit exception now when use untyped UDF.

### How was this patch tested?

Added test and updated some tests.

Closes #27488 from Ngone51/spark_26580_followup.

Lead-authored-by: yi.wu <[email protected]>
Co-authored-by: wuyi <[email protected]>
Signed-off-by: Wenchen Fan <[email protected]>
(cherry picked from commit 82ce475)
Signed-off-by: Wenchen Fan <[email protected]>
sjincho pushed a commit to sjincho/spark that referenced this pull request Apr 15, 2020
…F by default

### What changes were proposed in this pull request?

This PR proposes to throw exception by default when user use untyped UDF(a.k.a `org.apache.spark.sql.functions.udf(AnyRef, DataType)`).

And user could still use it by setting `spark.sql.legacy.useUnTypedUdf.enabled` to `true`.

### Why are the changes needed?

According to apache#23498, since Spark 3.0, the untyped UDF will return the default value of the Java type if the input value is null. For example, `val f = udf((x: Int) => x, IntegerType)`, `f($"x")` will  return 0 in Spark 3.0 but null in Spark 2.4. And the behavior change is introduced due to Spark3.0 is built with Scala 2.12 by default.

As a result, this might change data silently and may cause correctness issue if user still expect `null` in some cases. Thus, we'd better to encourage user to use typed UDF to avoid this problem.

### Does this PR introduce any user-facing change?

Yeah. User will hit exception now when use untyped UDF.

### How was this patch tested?

Added test and updated some tests.

Closes apache#27488 from Ngone51/spark_26580_followup.

Lead-authored-by: yi.wu <[email protected]>
Co-authored-by: wuyi <[email protected]>
Signed-off-by: Wenchen Fan <[email protected]>
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Labels

None yet

Projects

None yet

Development

Successfully merging this pull request may close these issues.

5 participants