[SPARK-29384] Support `ago` in interval strings

• Type: Sub-task
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 3.1.0
• Component/s: SQL
• Assignee: Unassigned
• Reporter: Max Gekk
• Created: 08/Oct/19 09:47
• Updated: 29/Mar/20 02:16

Description

PostgreSQL allow to specify direction in interval string by the `ago` word:

maxim=# select interval '@ 1 year 2 months 3 days 14 seconds ago';
              interval              
------------------------------------
 -1 years -2 mons -3 days -00:00:14

 See https://www.postgresql.org/docs/current/datatype-datetime.html#DATATYPE-INTERVAL-INPUT