presto-jmx/src/main/java/io/prestosql/plugin/jmx/JmxMetadata.java/JmxMetadata/listTableColumns
class JmxMetadata:    @Override
    public Map<SchemaTableName, List<ColumnMetadata>> listTableColumns(ConnectorSession session, SchemaTablePrefix prefix)
    {
        requireNonNull(prefix, "prefix is null");
        if (prefix.getSchema().isPresent() &&
                !prefix.getSchema().get().equals(JMX_SCHEMA_NAME) &&
                !prefix.getSchema().get().equals(HISTORY_SCHEMA_NAME)) {
            return ImmutableMap.of();
        }

        List<SchemaTableName> tableNames;
        if (!prefix.getTable().isPresent()) {
            tableNames = listTables(session, prefix.getSchema());
        }
        else {
            tableNames = ImmutableList.of(prefix.toSchemaTableName());
        }

        return tableNames.stream()
                .collect(toImmutableMap(Function.identity(), tableName -> getTableHandle(session, tableName).getTableMetadata().getColumns()));
    }