Alembic detects type change between LargeBinary and BLOB despite being equivalent in MySQL

[bomian98]

According to SQLAlchemy issue #3883, the LargeBinary type in SQLAlchemy should correspond to the BLOB type in MySQL. However, even though my ORM column is defined as LargeBinary and the actual database column type is BLOB, Alembic is still detecting this as a type change during migration. Why is this happening when these types should be considered equivalent?

And where is LONGBLOB comes, as the column type in MySQL is blob.

2025-07-21 13:28:59.973 - alembic.autogenerate.compare:(compare.py:1016) - INFO - Detected type change from LONGBLOB() to LargeBinary(length=4294967295) on 'xxxx'
2025-07-21 13:28:59.977 - alembic.autogenerate.compare:(compare.py:1016) - INFO - Detected type change from LONGBLOB() to LargeBinary(length=4294967295) on 'xxxx'