Unsupported SQL：

• RAL and RDL operations of DistSQL that are used in transactions.
• DDL support in XA transactions depends on the database dialect. PostgreSQL and openGauss permit only DDL statements that do not change metadata.

Privileges required for XA transactions:

In MySQL8, you need to grant the user XA_RECOVER_ADMIN privileges, otherwise, the XA transaction manager will report an error when executing the XA RECOVER statement.