Features Added in MySQL 8.0 FOR UPDATE  and  FOR SHARE  support  NOWAIT ,  SKIP LOCKED , and  OF  tbl_name  options. See Section 13.2.10, “SELECT Statement” . OF  tbl_name  applies locking queries to named tables. DROP PARTITION  with  ALGORITHM=INPLACE  deletes data stored in the partition and drops the partition. However,  DROP PARTITION  with  ALGORITHM=COPY  or  old_alter_table=ON  rebuilds the partitioned table and attempts to move data from the dropped partition to another partition with a compatible  PARTITION ... VALUES  definition. Data that cannot be moved to another partition is deleted. Undo tablespaces created using  CREATE UNDO TABLESPACE  syntax can be dropped at runtime using  DROP UNDO TABLESPACE  syntax. ALTER UNDO TABLESPACE  syntax can be used to mark an undo tablespace as active or inactive. A  STATE  column that shows the state of a tablespace was added to the INFORMATION_SCHEMA.INNODB_TABLESPACES  table. An undo tablespace must be in an  empty state before it can be dropped. 13 •The  innodb_rollback_segments  variable defines the number of rollback segments per undo tablespace. Previously,  innodb_rollback_segments  specified the total number of rollback segments for the MySQL instance. This change increases the number of rollback segments available for concurrent transactions. More rollback segments increases the likelihood that •The  innodb_undo_log_truncate  variable is enabled by default. •By default, undo logs now reside in two undo tablespaces that are created when the MySQL instance is initialized. Undo logs are no longer created in the system tablespace. •As of MySQL 8.0.14, additional undo tablespaces can be created in a chosen location at runtime using  CREATE UNDO TABLESPACE  syntax. • ADD PARTITION ,  DROP PARTITION ,  COALESCE PARTITION ,  REORGANIZE PARTITION , and REBUILD PARTITION ALTER TABLE  options are supported by native partitioning in-place APIs and may be used with  ALGORITHM={COPY|INPLACE}  and  LOCK  clauses. •The  InnoDB  storage engine now uses the MySQL data dictionary rather than its own storage engine- specific data dictionary. For information about the data dictionary, see Chapter 14,  MySQL Data Dictionary . • mysql  system tables and data dictionary tables are now created in a single  InnoDB  tablespace file named  mysql.ibd  in the MySQL data directory. Previously, these tables were created in individual InnoDB  tablespace files in the  mysql  database directory. •The following undo tablespace changes are introduced in MySQL 8.0: CREATE UNDO TABLESPACE  tablespace_name  ADD DATAFILE ’ file_name .ibu’; DROP UNDO TABLESPACE  tablespace_name ; ALTER UNDO TABLESPACE  tablespace_name  SET {ACTIVE|INACTIVE};