Performing MySQL schema changes often requires downtime for applications. In this blog, we cover two ways we can perform MySQL schema changes without risking downtime or other MySQL data problems. In this real-life customer example, we perform a schema change to modify the column data type from varchar(20) to varchar(50) on approx. 35 tables from 3GB to 10GB in size. Two of the tables are partitioned, and one of them is about 100GB combining all partitions for that table.
Online MySQL Schema Changes: An Example Procedure
Database Administration, Cluster Management, Zero Downtime Maintenance