I am trying to optimize the query to run faster. The query is the following:

SELECT grp_fk_obj_id, grp_name
FROM tbl_groups as g1
         CROSS APPLY (SELECT TOP 1 grp_id as gid
                      FROM tbl_groups as g2
                      WHERE g1.grp_fk_obj_id = g2.grp_fk_obj_id
                      ORDER BY g2.date_from DESC, ISNULL(date_to, '4000-01-01') DESC) as a
WHERE g1.grp_id = gid

grp_id is a primary key. grp_fk_obj_id is a foreign key to another object. There are indexes on both of these columns (I guess it comes as default).

It takes about half a second to complete but I need it to make work faster. I took a look at the execution plan and it shows that "Top N sort" has a cost of more than 90%. Also, I have noticed that if I remove a where clause inside the cross apply then it runs at least 5x faster, but I need that where clause in one way or another.

Do you see any possibilities to improve the performance of this query?

I am trying to optimize the query to run faster. The query is the following:

SELECT grp_fk_obj_id, grp_name
FROM tbl_groups as g1
         CROSS APPLY (SELECT TOP 1 grp_id as gid
                      FROM tbl_groups as g2
                      WHERE g1.grp_fk_obj_id = g2.grp_fk_obj_id
                      ORDER BY g2.date_from DESC, ISNULL(date_to, '4000-01-01') DESC) as a
WHERE g1.grp_id = gid

grp_id is a primary key. grp_fk_obj_id is a foreign key to another object. There are indexes on both of these columns (I guess it comes as default).

It takes about half a second to complete but I need it to make work faster. I took a look at the execution plan and it shows that "Top N sort" has a cost of more than 90%. Also, I have noticed that if I remove a where clause inside the cross apply then it runs at least 5x faster, but I need that where clause in one way or another.

Do you see any possibilities to improve the performance of this query?

EDIT: table creation DDL:

create table tbl_groups
(
    grp_id        bigint identity
        constraint PK_tbl_groups
            primary key,
    grp_fk_obj_id bigint      not null
        constraint FK_grp_fk_obj_id
            references tbl_other,
    grp_name      varchar(30) not null,
    date_from     date        not null,
    date_to       date
)
go

create index IDX_grp_fk_obj_id
    on tbl_groups (grp_fk_obj_id)
go

create index IDX_grp_name
    on tbl_groups (grp_name)
go