Liquibase uses NUMBER(10) to try to keep INTEGER sort of consistent with
other databases. How to best handle the mappings are going to get a good
overhaul soon. You can use biginteger as a type that will give you a
larger integer size, or just use type="NUMBER(*,0)" directly.
If you want to override it you can create you own IntType extension
with different logic in toDatabaseType(), or you could use
<modifySql> to fix up the generated NUMBER(10) for oracle.
Nathan