presto-base-jdbc/src/main/java/io/prestosql/plugin/jdbc/JdbcMetadata.java/JdbcMetadata/getTableMetadata
class JdbcMetadata:    @Override
    public ConnectorTableMetadata getTableMetadata(ConnectorSession session, ConnectorTableHandle table)
    {
        JdbcTableHandle handle = (JdbcTableHandle) table;

        ImmutableList.Builder<ColumnMetadata> columnMetadata = ImmutableList.builder();
        for (JdbcColumnHandle column : jdbcClient.getColumns(session, handle)) {
            columnMetadata.add(column.getColumnMetadata());
        }
        return new ConnectorTableMetadata(handle.getSchemaTableName(), columnMetadata.build());
    }