[CALCITE-4085] Improve nullability support for fields of structured type

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.24.0
• Component/s: core
• Labels: pull-request-available
• Assignee: Dawid Wysakowicz
• Reporter: Dawid Wysakowicz
• Created: 23/Jun/20 09:31
• Updated: 25/Jul/20 15:00
• Resolved: 15/Jul/20 09:11

Description

As discussed in https://lists.apache.org/thread.html/r602ac95fff23dd1ef974fb396df7be061ab861384ec42f5c57ce0bc2%40%3Cdev.calcite.apache.org%3E I would like to change the way a type of a field of a record is derived at couple of locations. This helps frameworks such as Apache Flink to build support for nullable records with not null fields.

I suggest to change:

• SqlDotOperator#deriveType
• SqlItemOperator#inferReturnType
• AliasNamespace#validateImpl
• RexBuilder#makeFieldAccessInternal
• SqlValidatorImpl.DeriveTypeVisitor#visit(SqlIdentifier)

Issue Links

• relates to: CALCITE-2464 Allow to set nullability for columns of structured types
• links to: GitHub Pull Request #2042
• links to: PR#2042