272 Changes in MySQL 8.0 partitioned table using any other storage engine must be altered—either to convert it to  InnoDB  or  NDB , or to remove its partitioning— before  upgrading the server, else it cannot be used afterwards. For information about converting  MyISAM  tables to  InnoDB , see Section 15.6.1.5, “Converting Tables from MyISAM to InnoDB” . A table creation statement that would result in a partitioned table using a storage engine without such support fails with an error ( ER_CHECK_NOT_IMPLEMENTED ) in MySQL 8.0. If you import databases from a dump file created in MySQL 5.7 (or earlier) using  mysqldump  into a MySQL 8.0 server, you must make sure that any statements creating partitioned tables do not also specify an unsupported storage engine, either by removing any references to partitioning, or by specifying the storage engine as  InnoDB or allowing it to be set as  InnoDB  by default. The procedure given at Section 2.11.5, “Preparing Your Installation for Upgrade” , describes how to identify partitioned tables that must be altered before upgrading to MySQL 8.0. Note See Section 24.6.2, “Partitioning Limitations Relating to Storage Engines” , for further information. As a result, the default character set and collation for new objects differ from previously unless an explicit character set and collation are specified. This includes databases and objects within them, such as tables, views, and stored programs. Assuming that the previous defaults were used, one way to preserve them is to start the server with these lines in the  my.cnf  file: In a replicated setting, when upgrading from MySQL 5.7 to 8.0, it is advisable to change the default character set back to the character set used in MySQL 5.7 before upgrading. After the upgrade is completed, the default character set can be changed to  utf8mb4 . Server Changes • Incompatible change : Several server error codes are not used and have been removed (for a list, see Features Removed in MySQL 8.0). Applications that test specifically for any of them should be updated. • Important change : The default character set has changed from  latin1  to  utf8mb4 . These system variables are affected: •The default value of the  character_set_server  and  character_set_database  system variables has changed from  latin1  to  utf8mb4 . •The default value of the  collation_server  and  collation_database  system variables has changed from  latin1_swedish_ci  to  utf8mb4_0900_ai_ci . • Incompatible change : As of MySQL 8.0.11, it is prohibited to start the server with a lower_case_table_names  setting that is different from the setting used when the server was initialized. The restriction is necessary because collations used by various data dictionary table fields are based on the  lower_case_table_names  setting that was defined when the server was initialized, and restarting the server with a different setting would introduce inconsistencies with respect to how identifiers are ordered and compared. •In MySQL 8.0.11, several deprecated features related to account management have been removed, such as use of the  GRANT  statement to modify nonprivilege characteristics of user accounts, the [mysqld] character_set_server=latin1 collation_server=latin1_swedish_ci