[CALCITE-3172] RelBuilder#empty does not keep aliases

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 1.21.0
• Component/s: core
• Labels: pull-request-available
• Assignee: Ruben Q L
• Reporter: Ruben Q L
• Created: 04/Jul/19 13:46
• Updated: 10/Sep/19 21:36
• Resolved: 08/Jul/19 07:01

Description

RelBuilder#empty method "Creates a relational expression that reads from an input and throws all of the rows away... The default implementation creates a Values with the same specified row type as the input". However, even though the "original" row-type is kept, its aliases are lost, which can lead to issues when building a plan (especially because this method is used internally by other methods, e.g. by RelBuilder#filter with an "always false" filter).

Issue Links

• links to: GitHub Pull Request #1298