[CALCITE-4977] Support Snapshot in RelMdColumnOrigins

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 1.29.0
• Fix Version/s: 1.30.0
• Component/s: core
• Labels: pull-request-available
• Assignee: Unassigned
• Reporter: Q Kang
• Created: 09/Jan/22 13:10
• Updated: 19/Mar/22 09:18
• Resolved: 11/Jan/22 06:39

Description

Currently `RelMdColumnOrigins` does not define a specialized method for `Snapshot` node. Thus, a request for origin column on a temporal query will always return NULL.

For example:

select productid from products_temporal
for system_time as of timestamp '2011-01-02 00:00:00' 

The origin column of `productid` is NULL.

We could simply propagate the call to its children like many other RelNode types do.

Issue Links

• links to: GitHub Pull Request #2680