Hi All.
I've been reading all the thread and I want to add a few points:
You can set enable_seqscan=off in small or easy queries, but in large
queries index can speed parts of the query and slow other, so I think it is
neccesary if you want Postgres to become a Wide-used DBMS that the planner
could be able to decide accuratelly, in the thread there is a point that
might be useful, it will be very interesting that the planner could learn
with previous executions, even there could be a warm-up policy to let
planner learn about how the DB is working, this info could be stored with DB
data, and could statistically show how use of index or seqscan works on
every column of the DB.
I think it will be useful hearing all users and not guiding only with our
own experience, the main objective is to make a versatil DBMS, It's very
easy to get down the need of improving indexes with single selects, but a
lot of us are not doing single select, so I think that point needs to be
heard.
Regards