[FLINK-29072] Migrate DDL-related schema handling to the new Schema framework

• Type: Technical Debt
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 1.16.0
• Component/s: Table SQL / API
• Assignee: Unassigned
• Reporter: Jane Chan
• Created: 23/Aug/22 03:27
• Updated: 21/Nov/22 03:21

Description

FLIP-164 introduces the new Schema framework. Yet all DDL-related functionalities (such as CREATE TABLE, CREATE TABLE LIKE, ALTER TABLE SET/RESET, ALTER TABLE ADD/DROP CONSTRAINT, SHOW CREATE TABLE, etc.) are based on the deprecated CatalogTableImpl and TableSchema.

The FLIP said, "For backward compatibility, we leave Catalog#createTable and Catalog#alterTable untouched." Therefore, issues like FLINK-18958, FLINK-28690, etc., cannot be resolved. And new functionalities like ALTER TABLE ADD/MODIFY face a dilemma of implementing against the new framework but lose backward consistency.

Fully migrating to the new framework takes a lot of effort and maybe a long-term plan, but at least it's the time to put it on the agenda to have a track.

Issue Links

• blocks: FLINK-21634 ALTER TABLE statement enhancement

Sub-Tasks

• Migrate TableSchema to Schema for Hive connector: Closed
• CatalogPropertiesUtil supports de/serializing column comment: Closed
• Migrate to new schema framework & show column comment: Closed
• Replace deprecated TableSchema with Schema in MergeTableLikeUtil: Closed
• Upgrade the deprecated UniqueConstraint to the new one: Open
• Replace deprecated TableSchema with Schema in OperationConverterUtils: Closed