[GitHub] [spark] cloud-fan commented on a change in pull request #27542: [SPARK-30790]The dataType of map() should be map

[GitBox <gi...@apache.org>]

cloud-fan commented on a change in pull request #27542: [SPARK-30790]The dataType of map() should be map<null,null>
URL: https://github.com/apache/spark/pull/27542#discussion_r377740365
 
 

 ##########
 File path: docs/sql-migration-guide.md
 ##########
 @@ -218,6 +218,8 @@ license: |
   
   - Since Spark 3.0, when the `array` function is called without any parameters, it returns an empty array of `NullType`. In Spark version 2.4 and earlier, it returns an empty array of string type. To restore the behavior before Spark 3.0, you can set `spark.sql.legacy.arrayDefaultToStringType.enabled` to `true`.
 
+  - Since Spark 3.0, when the `map` function is called without any parameters, it returns an empty map of `NullType`. In Spark version 2.4 and earlier, it returns an empty map of string type. To restore the behavior before Spark 3.0, you can set `spark.sql.legacy.mapDefaultToStringType.enabled` to `true`.
 
 Review comment:
   an empty map with `NullType` as key/value type.

----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
 
For queries about this service, please contact Infrastructure at:
users@infra.apache.org


With regards,
Apache Git Services

---------------------------------------------------------------------
To unsubscribe, e-mail: reviews-unsubscribe@spark.apache.org
For additional commands, e-mail: reviews-help@spark.apache.org