Re: cannot get stable function to use index

Andy Colson <andy@squeakycode.net> writes:
> On 12/30/2015 1:07 PM, Tom Lane wrote:
>> it seems like you've got some weird data statistics that are causing a
>> misestimate.  Could we see the pg_stats row for that tsvector column?
>> Or maybe even the actual data?

> The table exists in a schema named jasperia, I've been removing the name
> for simplicity.  The dump of the table is here:

Thanks very much for sharing the data.  But now I am well and truly
confused, because I still can't reproduce your results.  I get

regression=# explain analyze
select *
from search
where search_vec @@ to_tsquery('213 & E & 13 & ST & N:*');
                                                     QUERY PLAN
--------------------------------------------------------------------------------------------------------------------
 Bitmap Heap Scan on search  (cost=76.00..80.02 rows=1 width=72) (actual time=8.119..8.119 rows=1 loops=1)
   Recheck Cond: (search_vec @@ to_tsquery('213 & E & 13 & ST & N:*'::text))
   ->  Bitmap Index Scan on search_key  (cost=0.00..76.00 rows=1 width=0) (actual time=8.113..8.113 rows=1 loops=1)
         Index Cond: (search_vec @@ to_tsquery('213 & E & 13 & ST & N:*'::text))
 Total runtime: 8.210 ms

This is on 9.3 branch tip, not 9.3.9 which I don't have installed;
but I see no bug fixes related to GIN estimation in the commit logs
since 9.3.9.

Are you using any nondefault planner settings?  Anything else
unusual about your installation?

            regards, tom lane