Bopolissimus Platypus wrote:
> create table test (
> id serial primary key,
> t_end timestamp);
>
> there's an index:
> create index test_t_end on test(t_end);
>
> can or should a query like:
>
> select login,t_end from test order by t_end desc;
>
> use the index?
It can, but that does not mean that it is unconditionally the best
choice. The planner will make the decision.