seq scan horrible

gistfile1.txt

drake=# explain analyze select id from vertices where name_fts @@ plainto_tsquery('school') or description_fts @@ plainto_tsquery('school') limit 100;
                                                       QUERY PLAN                                                        
-------------------------------------------------------------------------------------------------------------------------
 Limit  (cost=0.00..201.42 rows=100 width=16) (actual time=53.723..356.704 rows=100 loops=1)
   ->  Seq Scan on vertices  (cost=0.00..9031.60 rows=4484 width=16) (actual time=53.721..356.685 rows=100 loops=1)
         Filter: ((name_fts @@ plainto_tsquery('school'::text)) OR (description_fts @@ plainto_tsquery('school'::text)))
         Rows Removed by Filter: 93311
 Total runtime: 356.751 ms
(5 rows)