Dan Fairs <dan(dot)fairs(at)gmail(dot)com> wrote:
> I have a query which is running slowly, and the query plan shows
> an unexpected sequence scan where I'd have expected the planner to
> use an index.
Looking at the actual row counts compared to run time, it appears
that the active portion of your data set is heavily cached. In such
an environment, I would add these lines to postgresql.conf, to
better model costs:
seq_page_cost = 0.1
random_page_cost = 0.1 # or maybe slightly higher
cpu_tuple_cost = 0.03
-Kevin