code: public void updateDatabaseDdl(String instanceId, String databaseId) {
      // [START updateDatabaseDdl]
      try {
        dbAdminClient
            .updateDatabaseDdl(
                instanceId,
                databaseId,
                Arrays.asList("ALTER TABLE Albums ADD COLUMN MarketingBudget INT64"),
                null)
            .get();
      } catch (ExecutionException e) {
        throw (SpannerException) e.getCause();
      } catch (InterruptedException e) {
        throw SpannerExceptionFactory.propagateInterrupt(e);
      }
      // [END updateDatabaseDdl]
    }
docs: [VARIABLE my_database_id]