[FLINK-16889] Support converting BIGINT to TIMESTAMP for TO_TIMESTAMP function

• Type: New Feature
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Component/s: Table SQL / API, Table SQL / Planner
• Labels: usability
• Assignee: Unassigned
• Reporter: Jark Wu
• Created: 31/Mar/20 17:11
• Updated: 02/Apr/21 06:40
• Resolved: 02/Apr/21 06:40

Description

Many users reported that it is not possible for now to define an event-time field or watermark on a BIGINT column.

Impala supports to convert BIGINT into TIMESTAMP value using TO_TIMESTAMP() function [1]. The BIGINT argument represents the number of seconds past the epoch.

I think it makes sense to support this for Flink's TO_TIMESTAMP(). It is the converse of the UNIX_TIMESTAMP() function, which produces a BIGINT representing the number of seconds past the epoch.

[1]: https://impala.apache.org/docs/build/html/topics/impala_datetime_functions.html#datetime_functions__to_timestamp

Issue Links

• is fixed by: FLINK-21622 Introduce function TO_TIMESTAMP_LTZ(numeric [, precision])
• is related to: FLINK-13561 Verify and correct time function's semantic for Blink planner
• relates to: FLINK-20162 Fix time zone problems for some time related functions
• relates to: FLINK-21617 FLIP-162: Consistent Flink SQL time function behavior