One can use @@big_tables variable to force temp.tables to be on-disk (Aria or MyiSAM).

However, window function crash with it:

create table ten(a int);

insert into ten values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);

set big_tables=1;

select rank() over (order by a) from ten;

The reason is that we pass wrong parameters to filesort(). filesort should produce a list of rowids for us, but it produces a list of

instead.

I know how to fix this.