On 1 March 2012 12:45, Marcin Mirosław <marcin@mejor.pl> wrote:
Hello, my example query (and explain) is: $ explain SELECT count(*) from (select * from users_profile order by id) u_p; QUERY PLAN --------------------------------------------------------------------------- Aggregate (cost=1.06..1.07 rows=1 width=0) -> Sort (cost=1.03..1.03 rows=2 width=572) Sort Key: users_profile.id -> Seq Scan on users_profile (cost=0.00..1.02 rows=2 width=572) (4 rows)
Meseems "order by id" can be ignored by planner. It should speed up query without side effect. I know the query should be fixed but this is real and simplified query from real application. Does postgresql team think ppostgres should be smarter than user and fix user queries? If answer is positive please treat this as "feature request". Thank you and regards, Marcin.
If you have only 2 rows in the table, then the plan really doesn't matter too much. Sorting two rows would be really fast :)
