On 13/11/13 20:21, Jeff Janes wrote:
> The planner uses the check constraints to reason about the relation
> between each partition separately and the query, not between the
> different partitions. So while it may be possible to know that all rows
> in 2013_4 must be greater than all in 2013_3, it doesn't make use of
> that, instead taking the greatest value from each partition and putting
> it in a priority queue. So the one row from each table acts as a
> sentinel to prove that more rows from that table are not needed.
That makes perfect sense. Thank you very much.
Torsten