[CALCITE-4616] AggregateUnionTransposeRule causes row type mismatch when some inputs have unique grouping key

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.26.0
• Fix Version/s: 1.28.0
• Component/s: core
• Labels: pull-request-available
• Assignee: Vladimir Ozerov
• Reporter: Vladimir Ozerov
• Created: 21/May/21 09:28
• Updated: 20/Oct/21 05:24
• Resolved: 13/Oct/21 23:28

Description

Consider the following relational tree:

1: Aggregate[group=a, SUM(b)]
2:   Union
3:     Input1[a, b, c]
4:     Input2[a, b, c]

It may happen, that Input1 has a unique key on [a]. In this case, Apache Calcite, will not install the Aggregate on top of it, which leads to the following tree:

1: Aggregate[group=a, SUM(b)]
2:   Union
3:     Input1[a, b, c]
4:     Aggregate[group=a, SUM(b)]
5:       Input2[a, b, c]

Obviously, the tree is incorrect, because Union inputs now have different row types.

Issue Links

• links to: GitHub Pull Request #2437