_

explain

Limit  (cost=1.28..2065.14 rows=51 width=648) (actual time=0.187..3411.776 rows=1 loops=1)
  Output: f0.id, f0.user_id, f0.post_id, p1.id, p1.body, p1.user_id, p1.nesting_level, p1.replies_count, p1.shares_count, p1.parent_id, p1.related_to_id, p1.old_attachment, p1.deleted_at, p1.inserted_at, p1.updated_at, p2.id, p2.body, p2.user_id, p2.nesting_level, p2.replies_count, p2.shares_count, p2.parent_id, p2.related_to_id, p2.old_attachment, p2.deleted_at, p2.inserted_at, p2.updated_at
  Buffers: shared hit=390937 read=186905
  ->  Nested Loop Left Join  (cost=1.28..780542.45 rows=19288 width=648) (actual time=0.186..3411.775 rows=1 loops=1)
        Output: f0.id, f0.user_id, f0.post_id, p1.id, p1.body, p1.user_id, p1.nesting_level, p1.replies_count, p1.shares_count, p1.parent_id, p1.related_to_id, p1.old_attachment, p1.deleted_at, p1.inserted_at, p1.updated_at, p2.id, p2.body, p2.user_id, p2.nesting_level, p2.replies_count, p2.shares_count, p2.parent_id, p2.related_to_id, p2.old_attachment, p2.deleted_at, p2.inserted_at, p2.updated_at
        Inner Unique: true
        Filter: ((p2.deleted_at IS NULL) OR (p1.body IS NOT NULL))
        Buffers: shared hit=390937 read=186905
        ->  Nested Loop  (cost=0.86..769854.37 rows=19430 width=336) (actual time=0.172..3411.761 rows=1 loops=1)
              Output: f0.id, f0.user_id, f0.post_id, p1.id, p1.body, p1.user_id, p1.nesting_level, p1.replies_count, p1.shares_count, p1.parent_id, p1.related_to_id, p1.old_attachment, p1.deleted_at, p1.inserted_at, p1.updated_at
              Inner Unique: true
              Buffers: shared hit=390933 read=186905
              ->  Index Scan Backward using feed_activity_pkey on public.feed_activity f0  (cost=0.44..715389.45 rows=19893 width=24) (actual time=0.127..3411.715 rows=1 loops=1)
                    Output: f0.id, f0.user_id, f0.post_id
                    Filter: (f0.user_id = 1)
                    Rows Removed by Filter: 20534851
                    Buffers: shared hit=390929 read=186905
              ->  Index Scan using posts_pkey on public.posts p1  (cost=0.42..2.74 rows=1 width=312) (actual time=0.043..0.043 rows=1 loops=1)
                    Output: p1.id, p1.body, p1.user_id, p1.parent_id, p1.nesting_level, p1.replies_count, p1.shares_count, p1.inserted_at, p1.updated_at, p1.related_to_id, p1.old_attachment, p1.deleted_at
                    Index Cond: (p1.id = f0.post_id)
                    Filter: (p1.deleted_at IS NULL)
                    Buffers: shared hit=4
        ->  Index Scan using posts_pkey on public.posts p2  (cost=0.42..0.54 rows=1 width=312) (actual time=0.012..0.012 rows=1 loops=1)
              Output: p2.id, p2.body, p2.user_id, p2.parent_id, p2.nesting_level, p2.replies_count, p2.shares_count, p2.inserted_at, p2.updated_at, p2.related_to_id, p2.old_attachment, p2.deleted_at
              Index Cond: (p2.id = p1.related_to_id)
              Buffers: shared hit=4
Planning Time: 0.715 ms
Execution Time: 3411.851 ms