Ronaldo Maia <romaia@async.com.br> writes:
> Recently I have tried to upgrade our postgres instalation from 9.1 to 9.3,
> but one query in particular got extremelly slow.
FWIW, this test case doesn't reproduce any problem for me --- I get
identical plans and indistinguishable timings (about 450ms on my machine)
from 9.1 and 9.3 branch tips. This is with all-default settings and
a VACUUM ANALYZE after loading the data. I had to guess at the definition
of stoq_normalize_string(), too, so I used
create function stoq_normalize_string(text) returns text language sql
strict immutable as 'select unaccent($1)';
I speculate that you forgot to analyze the data after loading, or there's
some performance-relevant setting that you didn't carry forward from the
9.1 database.
regards, tom lane