Backport to branch(3) : Revisit handling IS_NULL conditions on right source table columns in LEFT_OUTER virtual tables

[feeblefakie]

This is an automated backport of the following:

• Original PR: Revisit handling IS_NULL conditions on right source table columns in LEFT_OUTER virtual tables #3217
• Backported commit: d4a3a97

Please merge this PR after all checks have passed.

[gemini-code-assist]

Summary of Changes

Hello @feeblefakie, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This backported pull request enhances the handling of IS_NULL conditions on right source table columns within LEFT_OUTER virtual tables in the JDBC storage layer. It introduces a more robust and explicit approach to prevent ambiguous data modifications. Specifically, Put operations with all IS_NULL conditions on the right side will now default to PutIfNotExists, while Delete operations with similar conditions will be disallowed by default to avoid unintended data loss, with both behaviors being configurable through new operation attributes.

Highlights

• Refined LEFT_OUTER Join Handling: Implemented specific logic for Put and Delete operations on LEFT_OUTER virtual tables when IS_NULL conditions are applied to right source table columns to prevent ambiguous behavior.
• Put Operation Conversion: For Put operations, if all conditions on right-side columns are IS_NULL in a LEFT_OUTER join, the condition is now converted to PutIfNotExists by default. This behavior is controllable via a new operation attribute.
• Delete Operation Restriction: For Delete operations, if all conditions on right-side columns are IS_NULL in a LEFT_OUTER join, an IllegalArgumentException is thrown by default to prevent ambiguous deletions. This restriction can be overridden via a new operation attribute.
• New Error Code: Introduced a new error code, DELETE_IF_IS_NULL_FOR_RIGHT_SOURCE_TABLE_NOT_ALLOWED_FOR_LEFT_OUTER_VIRTUAL_TABLES, to clearly indicate the reason for disallowed delete operations.
• Operation Attributes Utility: Added a new utility class, JdbcOperationAttributes, to manage and configure these new behaviors for Put and Delete operations related to LEFT_OUTER virtual tables.

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[gemini-code-assist]

Code Review

This pull request refactors the handling of IS NULL conditions on columns from the right source table in LEFT_OUTER virtual tables. For Put operations, it now converts a PutIf with only IS NULL conditions on right-table columns to a PutIfNotExists by default. This is a sensible default to check for the non-existence of the right-side record. For Delete operations, it now disallows DeleteIf with only IS NULL conditions on right-table columns by default, due to semantic ambiguity. Both behaviors are made configurable through new operation attributes, which is a flexible approach. The changes are well-implemented and include comprehensive tests. My feedback includes a suggestion to improve the robustness of a new private helper method for better maintainability.