Add alter column type

[KodaiD]

Description

This PR adds support for altering column types in ScalarDB.

Currently, ScalarDB does not support altering column types and users must recreate tables to do so. This feature will provide more flexibility in managing database schemas without requiring recreating tables.

Related issues and/or PRs

• Support ifNotExists in add column #2960
• Add drop column #2983
• Add rename column #2990
• Add rename table #3021

Changes made

• Added alterColumnType method in the Admin interface.
• Added unit tests for the method.
• Added integration tests for the method.

Checklist

• I have commented my code, particularly in hard-to-understand areas.
• I have updated the documentation to reflect the changes.
• I have considered whether similar issues could occur in other products, components, or modules if this PR is for bug fixes.
• Any remaining open issues linked to this PR are documented and up-to-date (Jira, GitHub, etc.).
• Tests (unit, integration, etc.) have been added for the changes.
• My changes generate no new warnings.
• Any dependent changes in other PRs have been merged and published.

Additional notes (optional)

This PR does not consider imported tables. I will create another PR to handle those.

Release notes

Added support for altering column types in ScalarDB.

[KodaiD]

/gemini review

[gemini-code-assist]

Code Review

This pull request adds support for altering column types in ScalarDB, a significant feature enhancement. The changes are extensive, touching the admin interfaces, various storage implementations (JDBC, Cassandra, Cosmos, DynamoDB), and transaction layers. The implementation is mostly solid, with good test coverage. I've identified a few areas for improvement, including a bug with a duplicated error code, a minor inconsistency in exception handling, and opportunities to improve code readability and remove redundancy in tests. Overall, this is a great contribution.

[KodaiD]

/gemini review

[gemini-code-assist]

Code Review

This pull request introduces a significant new feature: altering column types. The changes are extensive, touching the admin interfaces, common logic, and specific implementations for various storage backends. The core logic for handling type alterations and the addition of numerous integration tests are commendable. My review focuses on improving resource management in the new tests and ensuring consistent error handling. Overall, this is a solid contribution that enhances the flexibility of schema management in ScalarDB.

[Copilot]

Pull Request Overview

This PR adds support for altering column types in ScalarDB, providing more flexibility in managing database schemas without requiring table recreation.

• Added alterColumnType method to the Admin interface and all implementations
• Implemented type conversion validation with storage-specific limitations
• Added comprehensive unit and integration tests for the new functionality

Reviewed Changes

Copilot reviewed 54 out of 54 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
core/src/main/java/com/scalar/db/api/Admin.java	Adds alterColumnType method to the Admin interface
core/src/main/java/com/scalar/db/common/CommonDistributedStorageAdmin.java	Implements type conversion validation logic
core/src/main/java/com/scalar/db/storage/jdbc/JdbcAdmin.java	Implements JDBC-specific column type alteration
core/src/main/java/com/scalar/db/storage/jdbc/RdbEngine*.java	Adds database-specific SQL generation for column type changes
core/src/main/java/com/scalar/db/transaction/consensuscommit/ConsensusCommitAdmin.java	Handles column type changes for both main and before-image columns
Various test files	Adds comprehensive unit and integration tests

---

_{Tip: Customize your code reviews with copilot-instructions.md. Create the file or learn how to get started.}

[KodaiD]

/gemini review

[gemini-code-assist]

Code Review

This pull request introduces a valuable feature for altering column types in ScalarDB, enhancing schema management flexibility. The implementation is well-structured, with a new alterColumnType method added to the Admin interface and correctly implemented across various storage backends. For databases that do not support this feature, such as Cassandra, Cosmos DB, and DynamoDB, the implementation appropriately throws an UnsupportedOperationException. The JDBC storage implementations are particularly thorough, covering specific SQL dialects and limitations for MySQL, PostgreSQL, SQL Server, Oracle, and Db2. The addition of comprehensive unit and integration tests ensures the reliability of this new functionality. Overall, this is a solid contribution. I have one minor suggestion to improve code readability.

[feeblefakie]

Overall, looking good.
Left some suggestions. PTAL!

[josh-wong]

LGTM! Thank you!🙇🏻‍♂️

[brfrn169]

Overall LGTM. Left a few comments. PTAL!

[feeblefakie]

LGTM! Thank you!

[komamitsu]

LGTM, thank you!

[KodaiD]

/gemini review

[gemini-code-assist]

Code Review

This pull request introduces support for altering column types in ScalarDB, a significant feature enhancement. The changes are extensive, touching the core Admin API, various storage implementations (JDBC, Cassandra, Cosmos, DynamoDB), and transaction managers. The implementation for JDBC databases is thorough, with specific handling for different RDB engines like Oracle, DB2, and SQLite. For storages that do not support this feature, it's correctly disabled. The integration and unit tests are comprehensive, covering various scenarios and database-specific behaviors. I've found one issue in the ConsensusCommitAdmin implementation that needs to be addressed. Overall, this is a well-executed PR that adds valuable flexibility to schema management.

[brfrn169]

LGTM! Thank you!

[brfrn169]

@Torch3333 I'll merge this PR. Please take a look when you are back!