Re: pgsql: Allow GiST distance function to return merely a lower-bound.

On 05/15/2015 03:05 PM, Fujii Masao wrote:
> Seems this patch causes the regression test of pg_trgm fail.
> The regression diff that I got is:
>
> *** /home/postgres/pgsql/head/contrib/pg_trgm/expected/pg_trgm.out
> 2013-07-23 16:46:22.212488785 +0900
> --- /home/postgres/pgsql/head/contrib/pg_trgm/results/pg_trgm.out
> 2015-05-15 20:59:16.574926732 +0900
> ***************
> *** 2332,2343 ****
>    (3 rows)
>
>    select t <-> 'q0987wertyu0988', t from test_trgm order by t <->
> 'q0987wertyu0988' limit 2;
> !  ?column? |      t
> ! ----------+-------------
> !  0.411765 | qwertyu0988
> !       0.5 | qwertyu0987
> ! (2 rows)
> !
>    drop index trgm_idx;
>    create index trgm_idx on test_trgm using gin (t gin_trgm_ops);
>    set enable_seqscan=off;
> --- 2332,2338 ----
>    (3 rows)
>
>    select t <-> 'q0987wertyu0988', t from test_trgm order by t <->
> 'q0987wertyu0988' limit 2;
> ! ERROR:  index returned tuples in wrong order
>    drop index trgm_idx;
>    create index trgm_idx on test_trgm using gin (t gin_trgm_ops);
>    set enable_seqscan=off;

Hmm, OK. pg_trgm works for me, but I'll take a look. (rover_firefly also
went red, due to rounding differences in the regression test)

- Heikki