Re: trgm regex index peculiarity

"Erik Rijkers" <er@xs4all.nl> writes:
> In a 112 MB test table (containing random generated text) with a trgm index (gin_trgm_ops), I consistently get these
timings:
> select txt from azjunk6 where txt ~ '^abcd';
>    130 ms
> select txt from azjunk6
> where txt ~ 'abcd' and substr(txt,1,4) = 'abcd';
>    3 ms

Hm, could you provide a self-contained test case?
        regards, tom lane