Description

This PR Supports concurrent copying of chunk blocks during each time slice of copying the existing data.

In case this PR introduced Go code changes:

• contributed code is using same conventions as original code
• script/cibuild returns with no formatting errors, build errors or unit test errors.

When the unique index used for copying blocks includes an auto-increment column, concurrency is blocked on the auto-inc lock. If the unique index used does not include an auto-increment column, concurrency can proceed.

May I ask when this feature will be reflected in the new version