PostgreSQL materialized view with global and partitioned ranks - postgresql

Question

I have a table with 10 mils. of user ratings.
I need to create materialized view that has global rating and rating by country and is refreshed once a day.
I came up with the following select query:
SELECT row_number() OVER(ORDER BY value DESC, id) AS rank_global,
row_number() OVER(PARTITION BY country ORDER BY value DESC, id) AS rank_country,
*
FROM rate
ORDER BY value DESC, id
LIMIT 100000
Is there a way to speed up this query or maybe there is another way to do the same? I created btree (value desc, id) and (country, value desc, id) indexes but it still takes a lot of time to complete.
Example:
Creating a table and populating it with users with random value column and random country:
CREATE TABLE rate
(
id serial NOT NULL,
name text,
value integer NOT NULL DEFAULT 0,
country character varying,
CONSTRAINT rate_pkey PRIMARY KEY (id)
);
INSERT INTO rate
(SELECT n, ('user_'||n), (random()*30)::int, ('country_'||(random()*3)::int)
FROM generate_series(0,10) AS n);
CREATE INDEX rate_country_value_id_index
ON rate
USING btree(country, value DESC, id);
CREATE INDEX rate_value_id_index
ON rate
USING btree(value DESC, id);
Table contents:
id name value country
0 user_0 28 country_2
1 user_1 24 country_2
2 user_2 29 country_1
3 user_3 11 country_1
4 user_4 16 country_1
5 user_5 28 country_0
6 user_6 3 country_1
7 user_7 7 country_1
8 user_8 28 country_1
9 user_9 4 country_0
10 user_10 29 country_1
Then I create materialized view:
CREATE MATERIALIZED VIEW rate_view AS
SELECT row_number() OVER (ORDER BY value DESC, id) AS rgl,
row_number() OVER (PARTITION BY country ORDER BY value DESC, id) AS rc,
*
FROM rate
ORDER BY value DESC, id;
View contents (rgl - global rank, rc - rank by country):
rgl rc id name value country
1 1 2 user_2 29 country_1
2 2 10 user_10 29 country_1
3 1 5 user_5 28 country_0
4 1 0 user_0 28 country_2
5 3 8 user_8 28 country_1
6 2 1 user_1 24 country_2
7 4 4 user_4 16 country_1
8 5 3 user_3 11 country_1
9 6 7 user_7 7 country_1
10 2 9 user_9 4 country_0
11 7 6 user_6 3 country_1
Now i can create complex queries to select users with closest rank and its neighbours by rank. Both globally and by country.
For example, (after creating (value,id) and (rgl) indexes on view) here is global top 50 and 5 users closest by rank to value 9999942:
(
WITH closest_rank AS
(
SELECT rgl FROM rate_view
WHERE value <= 9999942
ORDER BY value DESC, id ASC
LIMIT 1
)
SELECT rgl, name, value
FROM rate_view
WHERE rgl > (SELECT rgl-3 FROM closest_rank )
ORDER BY rgl ASC
LIMIT 5
)
UNION
SELECT rgl, name, value
FROM rate_view
WHERE rgl <=50
ORDER BY rgl;