I'm having a difficult time finding documentation on EXPLAIN PLAN stats. For example, in ' -> Nested Loop Left Join (cost=0.43..1415.06 rows=2 width=1377) (actual time=0.093..0.093 rows=0 loops=1)' what does 0.43..1415.06 mean? Is that a range? If so, it seems rather pointless, like saying "somewhere between 0 and infinity".
Thomas' link should cover this but it isn't giving you a probabilistic range , its giving the time to first record and time to fetch all records. For stuff like semi-joins you don't care about the total number of records found only that you can quickly find one record. A limited requirement but since plan output is somewhat generic in nature it always gives both numbers.
Also, is there a way to tell the query planner to limit the search for the best plan on a per statement basis. I know that this exists as a config parameter but I think that applies to the entire database. I have a query that takes 9 times more time to plan than it does to execute.
All parameters (in this context) are session-local in use; even if the default value is set at the scope of the entire server. You can make them transaction-local by using "SET LOCAL" instead of a plain "SET" when changing them within the session.