[CALCITE-6040] The operand type inference of SqlMapValueConstructor is incorrect

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.35.0
• Fix Version/s: 1.36.0
• Component/s: tests
• Labels: pull-request-available
• Assignee: Ran Tao
• Reporter: Ran Tao
• Created: 07/Oct/23 09:07
• Updated: 10/Nov/23 11:34
• Resolved: 20/Oct/23 11:29

Description

we have a simple test case:

f.checkScalar("map[1, null]", "{1=null}",
"(INTEGER NOT NULL, NULL) MAP NOT NULL"); 

The result is:

java.lang.AssertionError: Query: values (map[1, null])
Expected: is "(INTEGER NOT NULL, NULL) MAP NOT NULL"
     but: was "(INTEGER NOT NULL, INTEGER) MAP NOT NULL"

however, the asserted actual result "(INTEGER NOT NULL, INTEGER) MAP NOT NULL" for this case is wrong. If we switch to  this asserted actual result it throws another exception:

java.lang.AssertionError: Query: select map[p0, null] from (values (1)) as t(p0)
Expected: is "(INTEGER NOT NULL, INTEGER) MAP NOT NULL"
     but: was "(INTEGER NOT NULL, NULL) MAP NOT NULL"

No matter how you write this result type in this test case, it is wrong. 

by checking the plan, it seems the deduced value type of NULL has converted to INTEGER.

More serious scenario, if it is `map[1, 'x', 2, null]`, an exception will be thrown directly and fail.

because the null converted to FIRST_KNOWN INTEGER(however it should keep NULL, then leaseRestrictive type will be char). 

the form such as `map[1, null, 2,'x']` has same problem.

Issue Links

• links to: GitHub Pull Request #3463