Re: BUG #16863: Assert failed in set_plain_rel_size() on processing ~* with a long prefix - Mailing list pgsql-bugs

Alexander Lakhin <exclusion@gmail.com> writes:
> I've found a division that produces NaN:
> sel /= pow(FIXED_CHAR_SEL, fixed_prefix_len);

Hmm.  I'm not getting a NaN AFAICT, but I am getting pretty darn weird
estimates.  I agree this needs some kind of clamp.

regression=# create table test (t text);
CREATE TABLE
regression=# explain SELECT * FROM test WHERE t ~* ('^' || repeat('-', 500));
...
 Seq Scan on test  (cost=0.00..27.00
rows=10000000000000000159028911097599180468360808563945281389781327557747838772170381060813469985856815104width=32) 
...

BTW, the message you're answering hasn't shown up here, nor is it
in the mailing list archives.  Odd.

            regards, tom lane