create server abc_server foreign data wrapper file_fdw;
create foreign table file_table ( c1 text, i2 int, i3 int)
    server abc_server
    options ( filename '/tmp/table.txt', format 'csv', delimiter E'\t' );
select c1, i2, i3 from file_table order by c1; 
select c1, i2     from file_table order by i2 desc;
select c1, i3     from file_table order by i3 desc;
select c1
     , rank() over (order by i2 desc)  
     , rank() over (order by i3 desc)
from file_table
order by c1;