>> I'm not sure what "mixed" mode is supposed to be, but based on what
>> I've seen so far, I'm a skeptical of the idea that encouraging people
>> to raise default_statistics_target to 50 and turn on
>> constraint_exclusion is reasonable.
>
> Why?
Because both of those settings are strictly worse for my database than
the defaults. I don't have any partitioned tables, and see:
http://archives.postgresql.org/pgsql-hackers/2008-11/msg01837.php
>> I'm also a bit surprised that
>> there doesn't seem to be anything here that depends on the size of the
>> database, even order-of-magnitude. It seems like the right value for
>> checkpoint_segments, at least, might depend on that.
>
> What does checkpoint_segments have to do with the size of the database?
It seems unlikely that you would want 256 MB of checkpoint segments on
a database that is only 100 MB (or even 500 MB). But you might very
well want that on a database that is 1 TB.
...Robert