Limitations and considerations

The following limitations apply:

• Due to the way MySQL operates, when loading data to a Google Cloud SQL for MySQL target during a Full Load task, duplicate key errors will not be reported to the logs.

• When updating a column's value to its existing value, a zero rows affected is returned from MySQL (unlike Oracle and Microsoft SQL Server that perform an update of one row). This generates an entry in the attrep_apply_exceptions control table and the following warning:

  Some changes from the source database had no impact when applied to the target database. See attrep_apply_exceptions table for details.

• If you need to replicate 4-byte emoji characters, the target schema character set must be set to utf8mb4.