public static String dropExternalReadableTable(LoadConfiguration config, String prefix) {
		StringBuilder b = new StringBuilder();

		// unique table name
		String name = config.getTable() + "_ext_" + prefix;

		b.append("DROP EXTERNAL TABLE ");
		b.append(name);

		return b.toString();

	}
@param config the load configuration
@param prefix the prefix
@return the drop DDL
extensions/spring-xd-extension-gpfdist/src/main/java/org/springframework/xd/greenplum/support/SqlUtils.java