freshrss=# explain analyse select title from freshrss_freshrss_entry where content like '%ambulance%';
                                                       QUERY PLAN
-------------------------------------------------------------------------------------------------------------------------
 Seq Scan on freshrss_freshrss_entry  (cost=0.00..1904.16 rows=1 width=48) (actual time=54.970..405.760 rows=34 loops=1)
   Filter: (content ~~ '%ambulance%'::text)
   Rows Removed by Filter: 12808
 Planning Time: 0.562 ms
 Execution Time: 405.782 ms
(5 rows)

freshrss=# create extension pg_trgm;
CREATE EXTENSION

freshrss=# create index gin_trgm_index_content on freshrss_freshrss_entry using gin(content gin_trgm_ops);
CREATE INDEX

freshrss=# explain analyse select title from freshrss_freshrss_entry where content like '%ambulance%';
                                                            QUERY PLAN
----------------------------------------------------------------------------------------------------------------------------------
 Bitmap Heap Scan on freshrss_freshrss_entry  (cost=88.01..92.02 rows=1 width=48) (actual time=0.659..16.860 rows=34 loops=1)
   Recheck Cond: (content ~~ '%ambulance%'::text)
   Rows Removed by Index Recheck: 84
   Heap Blocks: exact=105
   ->  Bitmap Index Scan on gin_trgm_index_content  (cost=0.00..88.01 rows=1 width=0) (actual time=0.333..0.334 rows=118 loops=1)
         Index Cond: (content ~~ '%ambulance%'::text)
 Planning Time: 0.676 ms
 Execution Time: 16.898 ms
(8 rows)

freshrss=# explain analyse select title from freshrss_freshrss_entry where title ilike '%ambulance%' OR content ilike '%ambulance%';
                                                               QUERY PLAN
-----------------------------------------------------------------------------------------------------------------------------------------
 Bitmap Heap Scan on freshrss_freshrss_entry  (cost=520.02..527.84 rows=2 width=48) (actual time=1.378..60.193 rows=39 loops=1)
   Recheck Cond: (((title)::text ~~* '%ambulance%'::text) OR (content ~~* '%ambulance%'::text))
   Rows Removed by Index Recheck: 79
   Heap Blocks: exact=105
   ->  BitmapOr  (cost=520.02..520.02 rows=2 width=0) (actual time=0.553..0.555 rows=0 loops=1)
         ->  Bitmap Index Scan on gin_trgm_index_title  (cost=0.00..72.01 rows=1 width=0) (actual time=0.069..0.069 rows=8 loops=1)
               Index Cond: ((title)::text ~~* '%ambulance%'::text)
         ->  Bitmap Index Scan on gin_trgm_index_content  (cost=0.00..448.01 rows=1 width=0) (actual time=0.484..0.484 rows=118 loops=1)
               Index Cond: (content ~~* '%ambulance%'::text)
 Planning Time: 1.907 ms
 Execution Time: 60.224 ms
(11 rows)