The pt-online-schema-change tool runs DDL queries (ALTER) online so that the table is not locked for reads and writes. It is a commonly used tool by community users and customers. Using it on Amazon RDS requires knowing about some specific details. First, a high-level explanation of how the tool works.
This is an example from the documentation:
pt-online-schema-change --alter "ADD COLUMN c1 INT" D=sakila,t=actor
The tool runs an ALTER on the table “actor” from the database “sakila.” The alter adds a column named “c1” of type …[Read more]