Re: A very long running query....

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On 21/07/2012 21:11, Claudio Freire wrote:
On Sat, Jul 21, 2012 at 5:10 PM, Claudio Freire <klaussfreire@xxxxxxxxx> wrote:
<ioannis@xxxxxxxxxx> wrote:
             (feed_all_y2012m07.ship_pos_messages join
ais_server.ship_objects on (ship_pos_messages.obj_id = ship_objects.obj_id))
             on (message_copies.msg_id = ship_pos_messages.msg_id)
It's this part of the query that's taking 3.2 hours.

Move the filtered message_copies to a CTE, and the filtered
ship_pos_messages join to another CTE. That should (in my experience)
get you better performance.
Btw... did you try the hash thing?
Not yet as I am trying at present to simplify the index getting the georefs out of it. Don't know if this is a good idea but I though that since I am not testing (yet) any equality other than making sure that the georefs are not null or empty, I could avoid having it in the index, thus reducing its size a lot... At least for now.....

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