ant - Specify schema for doing liquibase diff in Oracle? -

i'm trying liquibase diff in oracle using ant script.

here's snippet preforms diff

<target name="diff-database">     <diffdatabasetochangelog         driver=${db.driver}"         url="${db.url}"         username="${db.username}"         password="${db.password}"          referenceurl="jdbc:oracle:thin@hostname:port:sid"         referenceusername="user1"         referencepassword="password1"          outputfile="changelog.xml"         classpathref="tools.class.path"     </diffdatabasetochangelog> </target> 

here's issue.

• the 2 databases need compare both oracle.
• for referencedb need access tables under user, call user2, login user2 disabled on server need run from.
• luckily have access referencedb under user, call user1, , user has privilege "select table". should able access tables user2 user1.

so given of information, how specify want use user2's tables reference db?

i've @ this page, haven't found solves problem.

it should referencedefaultschemaname parameter (http://www.liquibase.org/documentation/maven/maven_diff.html), according https://liquibase.jira.com/browse/core-2364 there issues (i've not triedit myself).