Hi Jeff
Thank you very much.
>I determined this by changing each cost parameter and running explain,
>to see how much each one changed the cost estimate (after verifying
>the overall plan did not change).
your method is so smart!
Jian Gao
2012/11/9 Jeff Janes
> On Wed, Nov 7, 2012 at 11:17 P
=?UTF-8?B?6auY5YGl?= writes:
> I want to see the explain plan for a simple query. My question is : How
> is the cost calculated?
In the case you're looking at, it's basically one random index page
fetch plus one random heap page fetch (hence 8.0), plus assorted CPU
costs making up the other
On Wed, Nov 7, 2012 at 11:17 PM, 高健 wrote:
> Hi all:
>
>
>
> I want to see the explain plan for a simple query. My question is : How
> is the cost calculated?
>
>
>
> The cost parameter is:
>
>
>
> random_page_cost= 4
>
> seq_page_cost = 1
>
> cpu_tuple_cost =0.01
>
Hi all:
I want to see the explain plan for a simple query. My question is : How
is the cost calculated?
The cost parameter is:
random_page_cost= 4
seq_page_cost = 1
cpu_tuple_cost =0.01
cpu_operator_cost =0.0025
And the table and its index physica
