Github user MaxGekk commented on a diff in the pull request:
https://github.com/apache/spark/pull/23196#discussion_r238111358
--- Diff: docs/sql-migration-guide-upgrade.md ---
@@ -33,6 +33,8 @@ displayTitle: Spark SQL Upgrading Guide
- Spark applications which are built with Spark version 2.4 and prior,
and call methods of `UserDefinedFunction`, need to be re-compiled with Spark
3.0, as they are not binary compatible with Spark 3.0.
+ - Since Spark 3.0, JSON datasource uses java.time API for parsing and
generating JSON content. New formatting implementation supports date/timestamp
patterns conformed to ISO 8601. To switch back to the implementation used in
Spark 2.4 and earlier, set `spark.sql.legacy.timeParser.enabled` to `true`.
--- End diff --
New implementation and old one have slightly different pattern formats. See
https://docs.oracle.com/javase/8/docs/api/java/time/format/DateTimeFormatter.html
and https://docs.oracle.com/javase/7/docs/api/java/text/SimpleDateFormat.html
. And two Java API can have different behaviours. Besides of that, new one can
parse timestamps with microseconds precision as a consequence of using Java 8
java.time API.
---
---------------------------------------------------------------------
To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org
For additional commands, e-mail: reviews-h...@spark.apache.org
