First, the function added in MySQL 8.0<\/p>\n
1, the new system dictionary table<\/p>\n
Integrated transaction data dictionary for storing information about database objects, all metadata is stored using the InnoDB engine<\/p>\n
2, support for DDL atomic operations<\/p>\n
The DDL of the InnoDB table supports transaction integrity, either to be successful or to roll back, to write the DDL operation rollback log to the data dictionary data dictionary table mysql.innodb_ddl_log for rollback operations<\/p>\n
3, security and user management<\/p>\n
Added caching_sha2_password authentication plugin and is the default authentication plugin.\u00a0Enhanced performance and security<\/p>\n
Permissions support role<\/p>\n
New password history feature restricts reuse of previous passwords<\/p>\n
4, support for resource management<\/p>\n
Supports creation and management of resource groups and allows the allocation of threads run by the server to specific groups for execution by threads based on the resources available to the resource group<\/p>\n
5, innodb enhancements<\/p>\n
Self-enhanced optimization to fix MySQL bug#199, this bug causes MySQL to take the maximum self-increment on the table as the maximum when the DB is restarted, and the next allocation is to allocate max(id)+1 if it is an archive table or After the data is deleted in other modes, the DB system restarts, and self-enhancement may be reused.<\/p>\n
Added INFORMATION_SCHEMA.INNODB_CACHED_INDEXES to see the index pages of each index cache in the InnoDB buffer pool<\/p>\n
InnoDB temporary tables will be created in the shared temporary table space ibtmp1<\/p>\n
InnoDB supports NOWAIT and SKIP LOCKED for SELECT … FOR SHARE and SELECT … FOR UPDATE statements<\/p>\n
The minimum value of innodb_undo_tablespaces is 2, and it is no longer allowed to set innodb_undo_tablespaces to 0.\u00a0Min 2 ensures that rollback segments are always created in the undo tablespace, not in the system tablespace<\/p>\n
ALTER TABLESPACE … RENAME TO syntax<\/p>\n
Added innodb_dedicated_server to let InnoDB automatically configure innodb_buffer_pool_size according to the amount of memory detected on the server, innodb_log_file_size, innodb_flush_method<\/p>\n
New INFORMATION_SCHEMA.INNODB_TABLESPACES_BRIEF view<\/p>\n
A new dynamic configuration item, innodb_deadlock_detect, is used to disable deadlock checking, because in high-concurrency systems, when a large number of threads wait for the same lock, deadlock checking can significantly slow down the database.<\/p>\n
Supports use of the innodb_directories option to move or restore tablespace files to a new location when the server is offline<\/p>\n
6, MySQL 8.0 better support for document database and JSON<\/p>\n
7, optimization<\/p>\n