Re: Why is this query not using GIN index?

On Sun, Nov 13, 2016 at 2:50 PM, Aaron Lewis <the(dot)warl0ck(dot)1989(at)gmail(dot)com>
wrote:

> I have a simple table, and a gin index,
>
> create table mytable(hash char(40), title varchar(500));
> create index name_fts on mytable using gin(to_tsvector('english',
> 'title'));
>

^^^^^

> create unique index md5_uniq_idx on mytable(hash);
>
> When I execute a query with tsquery, the GIN index was not in use:
>
> test=# explain analyze select * from mytable where
> to_tsvector('english', title) @@ 'abc | def'::tsquery limit 10;
> QUERY PLAN
> ------------------------------------------------------------
> --------------------------------------------------------
> Limit (cost=0.00..277.35 rows=10 width=83) (actual
> time=0.111..75.549 rows=10 loops=1)
> -> Seq Scan on mytable (cost=0.00..381187.45 rows=13744 width=83)
> (actual time=0.110..75.546 rows=10 loops=1)
> Filter: (to_tsvector('english'::regconfig, (title)::text) @@
> '''abc'' | ''def'''::tsquery)
> Rows Removed by Filter: 10221
> Planning time: 0.176 ms
> Execution time: 75.564 ms
> (6 rows)
>
> Any ideas?
>
>
> --
> Best Regards,
> Aaron Lewis - PGP: 0x13714D33 - http://pgp.mit.edu/
> Finger Print: 9F67 391B B770 8FF6 99DC D92D 87F6 2602 1371 4D33
>
>
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