Hi, Thank you.

> What about the performance in FB with your original SELECT MAX...
> after adding DESC index? And memory usage with FB?

I added both index and desc index to that field, using the command
below:

CREATE INDEX IX_A ON TABLE_X (field_A);
CREATE DESC INDEX IX_A_DE ON TABLE_X (field_A);

but seems not worked.
The execution will still take as long time as before.
and so is memory usage.