iBatis Java: Dynamic table names in DELETE

Question

iBatis 3 has a wonderful ability in SELECT statements to provide dynamic substitution before statement is prepared. For example this will work

<select id="foo">SELECT * FROM $db$.MY_TABLE</select>

However I can't make it work when trying to empty table

XML code:

<delete id="del" parameterType="String">DELETE FROM $db$.MY_TABLE</delete>
<!-- and I also tried -->
<delete id="del" parameterType="String">DELETE FROM $0$.MY_TABLE</delete>

Java code:

// method defined as
del(String db);
// and executed as
mapper.del("MY_DB");

I get message complaining that Database '$db$' does not exist

Anyone can suggest the solution? I'm on Teradata db and it is setup in the way that I need provide db names in query or else I get Object not found