[CALCITE-5961] Type inference of ARRAY_COMPACT is incorrect

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.35.0
• Fix Version/s: 1.36.0
• Component/s: core
• Labels: pull-request-available
• Assignee: Ran Tao
• Reporter: Ran Tao
• Created: 28/Aug/23 05:16
• Updated: 10/Nov/23 11:34
• Resolved: 19/Sep/23 23:57

Description

The return type of

array_compact(array[null, 1, null, 2])

is INTEGER ARRAY NOT NULL, but from semantics the correct type should be
INTEGER NOT NULL ARRAY NOT NULL.

because the returned result can not has NULL value.

currently, array_compact use ARG0_NULLABLE which is not enough.

  public static final SqlFunction ARRAY_COMPACT =
      SqlBasicFunction.create(SqlKind.ARRAY_COMPACT,
          ReturnTypes.ARG0_NULLABLE,
          OperandTypes.ARRAY);

Issue Links

• is related to: CALCITE-5734 Add ARRAY_COMPACT for Spark dialect
• links to: GitHub Pull Request #3405