Switching FOREIGN_KEY_CHECKS back on does not check the rows loaded
meanwhile, and DDL would commit halfway, so on MySQL every foreign key is
checked with a query for rows that point at nothing, before the commit.
The recorded table structure now keeps index options (the prefix lengths
MySQL needs for long text columns) and foreign keys; tables the restore
creates get their foreign keys after the commit.
The full-restore test also runs on MariaDB.
dillard
4f6a2e5b70