Refactor JdbcAdmin (Part 2)

[brfrn169]

Description

This PR continues the refactoring of JdbcAdmin (following #3121).

Related issues and/or PRs

• Refactor JdbcAdmin #3121

Changes made

• Adjusted the timing of metadata schema creation and deletion.
• Renamed tableExistsInternal()to internalTableExists().

Checklist

The following is a best-effort checklist. If any items in this checklist are not applicable to this PR or are dependent on other, unmerged PRs, please still mark the checkboxes after you have read and understood each item.

• 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)

N/A

Release notes

N/A

[gemini-code-assist]

Summary of Changes

Hello @brfrn169, 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 pull request continues the refactoring of the JdbcAdmin component, focusing on improving the clarity and control over metadata schema management. It centralizes the creation and deletion of the metadata schema within JdbcAdmin itself, ensuring that the schema is created explicitly when needed and removed only when truly empty. Additionally, it standardizes the naming of internal table existence check methods for better consistency.

Highlights

• Metadata Schema Creation Timing: The timing of metadata schema creation has been adjusted. Instead of being created implicitly when the namespaces table is created, the metadata schema is now explicitly created earlier in the process, such as during namespace or table creation, import, repair, or upgrade operations within JdbcAdmin.
• Method Renaming: The internal method tableExistsInternal() has been consistently renamed to internalTableExists() across DynamoAdmin, JdbcAdmin, NamespaceMetadataService, and TableMetadataService. Similarly, the corresponding RDB engine strategy method tableExistsInternalTableCheckSql() has been renamed to internalTableExistsCheckSql().
• Code Cleanup in NamespaceMetadataService: Redundant calls to createSchemaIfNotExists and deleteMetadataSchema have been removed from NamespaceMetadataService as the responsibility for metadata schema management has been centralized in JdbcAdmin.
• Test Adjustments: Integration and unit tests have been updated to reflect the changes in metadata schema creation timing and method names, ensuring that the new logic is correctly tested and verified.

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[gemini-code-assist]

Code Review

This pull request continues the refactoring of JdbcAdmin. The main changes are adjusting the timing of metadata schema creation to be lazy and renaming tableExistsInternal() to internalTableExists() for better clarity. The changes look good and improve the code structure. I've found a minor issue in the test updates for SQLite where the mocking seems incorrect. Please see my detailed comment.

[Copilot]

Pull Request Overview

This PR continues the refactoring of JdbcAdmin by improving the structure and timing of metadata schema management, and renaming a method for better clarity.

• Renamed tableExistsInternal() to internalTableExists() for improved naming consistency
• Moved metadata schema creation responsibility from NamespaceMetadataService to JdbcAdmin level for better separation of concerns
• Adjusted metadata schema deletion to occur at the JdbcAdmin level after namespace operations

Reviewed Changes

Copilot reviewed 14 out of 14 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
core/src/main/java/com/scalar/db/storage/jdbc/JdbcAdmin.java	Added createMetadataSchemaIfNotExists() and deleteMetadataSchemaIfEmpty() methods; renamed tableExistsInternal() to internalTableExists(); added metadata schema creation calls before operations that require it
core/src/main/java/com/scalar/db/storage/jdbc/NamespaceMetadataService.java	Removed metadata schema creation and deletion logic, now handled at JdbcAdmin level; renamed tableExistsInternal() to internalTableExists()
core/src/main/java/com/scalar/db/storage/jdbc/TableMetadataService.java	Renamed tableExistsInternal() to internalTableExists()
core/src/main/java/com/scalar/db/storage/jdbc/RdbEngineStrategy.java	Renamed interface method tableExistsInternalTableCheckSql() to internalTableExistsCheckSql()
core/src/main/java/com/scalar/db/storage/jdbc/RdbEngineMysql.java	Renamed method tableExistsInternalTableCheckSql() to internalTableExistsCheckSql()
core/src/main/java/com/scalar/db/storage/jdbc/RdbEnginePostgresql.java	Renamed method tableExistsInternalTableCheckSql() to internalTableExistsCheckSql()
core/src/main/java/com/scalar/db/storage/jdbc/RdbEngineOracle.java	Renamed method tableExistsInternalTableCheckSql() to internalTableExistsCheckSql()
core/src/main/java/com/scalar/db/storage/jdbc/RdbEngineSqlServer.java	Renamed method tableExistsInternalTableCheckSql() to internalTableExistsCheckSql()
core/src/main/java/com/scalar/db/storage/jdbc/RdbEngineSqlite.java	Renamed method tableExistsInternalTableCheckSql() to internalTableExistsCheckSql()
core/src/main/java/com/scalar/db/storage/jdbc/RdbEngineDb2.java	Renamed method tableExistsInternalTableCheckSql() to internalTableExistsCheckSql()
core/src/main/java/com/scalar/db/storage/dynamo/DynamoAdmin.java	Renamed method tableExistsInternal() to internalTableExists() for consistency
core/src/test/java/com/scalar/db/storage/jdbc/JdbcAdminTest.java	Updated test parameter ordering to match new execution flow; added mocks for metadata schema operations; removed obsolete metadata schema creation mocks from createNamespacesTableIfNotExists tests
core/src/integration-test/java/com/scalar/db/storage/jdbc/JdbcAdminTestUtils.java	Updated to use renamed method internalTableExistsCheckSql()
core/src/integration-test/java/com/scalar/db/storage/multistorage/MultiStorageAdminTestUtils.java	Updated to use renamed method internalTableExistsCheckSql()

Comments suppressed due to low confidence (1)

core/src/test/java/com/scalar/db/storage/jdbc/JdbcAdminTest.java:3974

• This Statement is not always closed on method exit.

    verify(adminSpy).createNamespacesTableIfNotExists(connection);

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[Torch3333]

LGTM, thank you!

[feeblefakie]

The code looks good, so I'm approving it.
But, can you clarify the reason for the changes?

[komamitsu]

LGTM 👍 other than @feeblefakie's comment.