tiktok=> \d videos
                           Table "public.videos"
   Column   |            Type             | Collation | Nullable | Default
------------+-----------------------------+-----------+----------+---------
 id         | character varying(64)       |           | not null |
 author     | character varying(128)      |           | not null |
 video_info | jsonb                       |           | not null |
 loaded     | boolean                     |           |          | false
 load_error | boolean                     |           |          | false
 fetching   | timestamp without time zone |           |          |
 also       | boolean                     |           |          |
Indexes:
    "videos_pkey" PRIMARY KEY, btree (id)
    "video_also_idx" btree (also)
    "video_check_idx" btree (loaded, load_error)
    "video_useful_idx" btree (loaded, load_error)
    "videos_author_idx" btree (author)
    "videos_fetching_idx" btree (fetching)
    "videos_info_idx" gin (video_info jsonb_path_ops)
    "videos_loaded_idx" btree (loaded)
Foreign-key constraints:
    "videos_author_fkey" FOREIGN KEY (author) REFERENCES authors(user_id)

tiktok=> explain analyze select id, loaded, also from videos where author = '6805721275644134406' and not loaded order by random() limit 50;
                                                                        QUERY PLAN
-----------------------------------------------------------------------------------------------------------------------------------------------------------
 Limit  (cost=411.72..411.85 rows=50 width=29) (actual time=810.168..810.174 rows=22 loops=1)
   ->  Sort  (cost=411.72..420.77 rows=3621 width=29) (actual time=810.166..810.169 rows=22 loops=1)
         Sort Key: (random())
         Sort Method: quicksort  Memory: 26kB
         ->  Bitmap Heap Scan on videos  (cost=278.37..291.43 rows=3621 width=29) (actual time=810.125..810.144 rows=22 loops=1)
               Recheck Cond: ((author)::text = '6805721275644134406'::text)
               Filter: (NOT loaded)
               Heap Blocks: exact=6
               ->  BitmapAnd  (cost=278.37..278.37 rows=1 width=0) (actual time=810.103..810.103 rows=0 loops=1)
                     ->  Bitmap Index Scan on videos_author_idx  (cost=0.00..131.75 rows=3624 width=0) (actual time=0.047..0.047 rows=23 loops=1)
                           Index Cond: ((author)::text = '6805721275644134406'::text)
                     ->  Bitmap Index Scan on videos_loaded_idx  (cost=0.00..144.56 rows=6399 width=0) (actual time=804.432..804.432 rows=6783464 loops=1)
                           Index Cond: (loaded = false)
 Planning Time: 0.254 ms
 Execution Time: 810.225 ms
(15 rows)

tiktok=> explain analyze with author_v as ( select id, loaded, also from videos where author = '6805721275644134406' ) select * from author_v where not loaded order by random() limit 50;
                                                                QUERY PLAN
-------------------------------------------------------------------------------------------------------------------------------------------
 Limit  (cost=14628.41..14628.54 rows=50 width=156) (actual time=0.103..0.108 rows=22 loops=1)
   CTE author_v
     ->  Index Scan using videos_author_idx on videos  (cost=0.57..14491.19 rows=3625 width=21) (actual time=0.040..0.060 rows=23 loops=1)
           Index Cond: ((author)::text = '6805721275644134406'::text)
   ->  Sort  (cost=137.22..141.75 rows=1812 width=156) (actual time=0.102..0.104 rows=22 loops=1)
         Sort Key: (random())
         Sort Method: quicksort  Memory: 26kB
         ->  CTE Scan on author_v  (cost=0.00..77.03 rows=1812 width=156) (actual time=0.046..0.084 rows=22 loops=1)
               Filter: (NOT loaded)
               Rows Removed by Filter: 1
 Planning Time: 0.200 ms
 Execution Time: 0.141 ms
(12 rows)