MySQL Online Schema Change Example using Percona

gistfile1.txt

#!/bin/bash

pt-online-schema-change \
       	--execute \
	--progress time,1 \
    	--print \
    	--recursion-method=none \
	-h my_host \
        -u root \
	--ask-pass \
        --alter-foreign-keys-method drop_swap \
	--alter "ADD COLUMN aaa bigint NULL, ADD CONSTRAINT bbb FOREIGN KEY (ccc) REFERENCES ddd(eee)" \
	D=my_db,t=my_table