code: public static void delete (String feedId, DataSource dataSource) throws SQLException, InvalidNamespaceException {
          LOG.info("Deleting all tables (dropping schema) for {} feed namespace.", feedId);
          Connection connection = null;
          try {
              connection = dataSource.getConnection();
              ensureValidNamespace(feedId);
              // Mark entry in feeds table as deleted.
              String deleteFeedEntrySql = "update feeds set deleted = true where namespace = ?";
              PreparedStatement deleteFeedStatement = connection.prepareStatement(deleteFeedEntrySql);
              deleteFeedStatement.setString(1, feedId);
              deleteFeedStatement.executeUpdate();
              // Drop all tables bearing the feedId namespace.
              // Note: It does not appear to be possible to use prepared statements with "drop schema."
              String dropSchemaSql = String.format("DROP SCHEMA %s CASCADE", feedId);
              Statement statement = connection.createStatement();
              statement.executeUpdate(dropSchemaSql);
              // Commit the changes.
              connection.commit();
          } catch (InvalidNamespaceException | SQLException e) {
              LOG.error(String.format("Could not drop feed for namespace %s", feedId), e);
              throw e;
          } finally {
              if (connection != null) DbUtils.closeQuietly(connection);
          }
      }
docs: Deletes all tables for the specified feed. Simply put, this is a "drop schema" SQL statement called on the feed's
  namespace.