Directory Structure

com
example
db
changelog
db.changelog-master.xml
db.changelog-1.0.xml
db.changelog*1.1.xml
db.changelog-2.0.xml
DatabasePool.java
AbstractDAO.java

db.changelog-master.xml

The master.xml includes the changelog for the releases in the correct order. In the example above it could look like this:

<?xml version="1.0" encoding="UTF-8"?>
<databaseChangeLog
xmlns=" http://www.liquibase.org/xml/ns/dbchangelog/1.9"
xmlns:xsi=" http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation=" http://www.liquibase.org/xml/ns/dbchangelog/1.9
http://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-1.9.xsd">

<include file="com/example/db/changelog/db.changelog-1.0.xml"/>
<include file="com/example/db/changelog/db.changelog-1.1.xml"/>
<include file="com/example/db/changelog/db.changelog-2.0.xml"/>
</databaseChangeLog>

The db.changelog-master.xml is the changelog you pass to all Liquibase calls.