On 13-04-10 09:56 AM, ktm@xxxxxxxx wrote:
On Wed, Apr 10, 2013 at 09:49:55AM -0400, Steve Singer wrote:
Hi Steve, The one thing that stands out to me is that you are working with 200GB of data on a machine with 4-8GB of ram and you have the random_page_cost set to 2.0. That is almost completely uncached and I would expect a value of 10 or more to be closer to reality.
Setting random_page_cost to 15 makes the planner choose the nested-loop plan (at least the date range I tried).
I thought that the point of effective cache size was to tell the planner high likely it is for a random page to be in cache. With 200GB of data for this query and an effective cache size of 3.5 GB I would have expected that to be accounted for.
Regards, Ken
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