Earlier last week, Oracle released their Q2 releases series. Unlike previous releases, backward compatibility has now been broken with previous versions of MySQL.
MySQL 8.0.29 extended the support for the online DDL algorithm INSTANT. Prior to 8.0.29 only adding columns to the end of the table was supported.
In 8.0.29, this functionality was extended to allow the INSTANT algorithm the ability to add columns in any position of the table as well to drop columns. This new functionality required the redo log version to increase and new redo log types to be added, thus making it incompatible with older versions of the MySQL server and also older versions of Percona Xtrabackup. Please note that an in-place minor version downgrade of …[Read more]