fix: [TD-38729] Forbid virtual table's timestamp precision different …

[Simon9997]

…from origin table's timestamp precision.

Description

Please briefly describe the code changes in this pull request.

Jira: https://jira.taosdata.com:18080/browse/TD-

Checklist

Please check the items in the checklist if applicable.

• Is the user manual updated?
• Are the test cases passed and automated?
• Is there no significant decrease in test coverage?

[gemini-code-assist]

Summary of Changes

Hello @Simon9997, 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 addresses an issue where virtual tables could be created or modified to reference origin tables with differing timestamp precisions, potentially leading to data inconsistencies. The changes introduce a strict validation mechanism at the parser level, preventing such configurations and enhancing data integrity. This ensures that all components interacting with time-series data maintain a consistent understanding of time granularity.

Highlights

• Timestamp Precision Enforcement: Implemented a new validation to ensure that virtual tables and their referenced origin tables have matching timestamp precisions.
• Parser Function Update: The checkColRef function in the parser was modified to include precision validation and its calls were updated across various ALTER TABLE and CREATE VTABLE operations.
• Comprehensive Test Cases: New test cases were added to cover scenarios where virtual tables are created or altered with references to tables having different timestamp precisions, ensuring the new validation works as expected.

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[gemini-code-assist]

Code Review

This pull request aims to prevent creating or altering virtual tables where the timestamp precision differs from the referenced original table. The changes correctly update the checkColRef function and its call sites for ALTER TABLE and CREATE VTABLE ... USING statements. However, there is a critical issue in the implementation for CREATE VTABLE (normal virtual table) where the database precision is not correctly retrieved, leading to incorrect validation. I've added a comment with a suggested fix. The added test cases are good but miss a positive case for non-default precision which would have exposed the bug.