[SPARK-31892] Disable week-based date filed for parsing

• Type: Sub-task
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.0.0, 3.1.0
• Fix Version/s: 3.0.0
• Component/s: SQL
• Assignee: Kent Yao 2
• Reporter: Kent Yao 2
• Created: 02/Jun/20 08:41
• Updated: 04/Jun/20 04:11
• Resolved: 03/Jun/20 06:53

Description

It's an un-fixable behavior change to fill the gap between SimpleDateFormat and DateTimeFormater and backward-compatibility for different JDKs.

A lot of effort has been made to prove this at https://github.com/apache/spark/pull/28674

The existing behavior itself in 2.4 is confusing, e.g.

spark-sql> select to_timestamp('1', 'w');
1969-12-28 00:00:00
spark-sql> select to_timestamp('1', 'u');
1970-01-05 00:00:00

the 'u' here seems not to go to the Monday of the first week in week-based form or the first day of the year in non-week-based form but go to the Monday of the second week in week-based form.

spark-sql> select to_timestamp('2020 2020', 'YYYY yyyy');
2020-01-01 00:00:00
spark-sql> select to_timestamp('2020 2020', 'yyyy YYYY');
2019-12-29 00:00:00
spark-sql> select to_timestamp('2020 2020 1', 'YYYY yyyy w');
NULL
spark-sql> select to_timestamp('2020 2020 1', 'yyyy YYYY w');
2019-12-29 00:00:00

I think we don't need to introduce all the weird behavior from Java.

Issue Links

• relates to: SPARK-31868 Wrong results for week-based-year
• links to: [Github] Pull Request #28706 (yaooqinn)
• links to: [Github] Pull Request #28718 (yaooqinn)