The 5.7.4 changelog begins with the following, so I felt it appropriate to include it here as well.
“This release is dedicated to the memory of two young engineers of the MySQL Engineering family, Astha and Akhila, whom we lost while they were in their early twenties. This is a small remembrance and a way to recognize your contribution to the 5.7 release. You will be missed.”
As for the fixes, there are quite a few, which is to be expected in such an early milestone release.
The main highlights for me were:
- The Performance Schema now instruments prepared statements (for both the binary and text protocols). Info is available in the prepared_statements_instances table, along with performance_schema_max_prepared_statements_instances system variable, and Performance_schema_prepared_statements_lost status variable.
- Incompatible Change: MySQL deployments installed using RPM packages now are secure by default (single root account, ‘root’@'localhost’, no anonymous-user accounts, no test database).
- Incompatible Change: MySQL now enables database administrators to establish a policy for automatic password expiration: Any user who connects to the server using an account for which the password is past its permitted lifetime must change the password.
- Performance; InnoDB: InnoDB now supports multiple page_cleaner threads for flushing dirty pages from buffer pool instances. A new system variable, innodb_page_cleaners, is used to specify the number of page_cleaner threads.
- Incompatible Change: The AES_ENCRYPT() and AES_DECRYPT() functions now permit control of the block encryption mode and take an optional initialization vector argument
- InnoDB: InnoDB now supports the Transportable Tablespace feature for partitioned InnoDB tables and individual InnoDB table partitions. This enhancement eases backup procedures for partitioned tables and enables copying of partitioned tables and individual table partitions between MySQL instances.
Of course, there were many, many more fixes/updates (InnoDB being #1, Replication #2, and Partitioning #3 with most fixed bugs), so be sure to read through the full changelog. And if you are running a previous version of *5.7*, then definitely plan on upgrading to this latest 5.7.4.
Hope this helps.