public String getUUID() {
        if (CatalogMgr.isExternalCatalog(catalogName)) {
            return catalogName + "." + fullQualifiedName;
        }
        return Long.toString(id);
    }
@Test
    public void testGetUUID() {
        // Internal database
        Database db1 = new Database();
        Assert.assertEquals("0", db1.getUUID());

        Database db2 = new Database(101, "db2");
        Assert.assertEquals("101", db2.getUUID());

        // External database
        Database db3 = new Database(101, "db3");
        db3.setCatalogName("hive");
        Assert.assertEquals("hive.db3", db3.getUUID());
    }