Re: postgresql scalability issue

umut orhan <umut_angelfire@yahoo.com> writes:
> When I pin a single query to an individual core, its execution time is observed 
> as 111 seconds. This result is my base case. Then, I fire two instances of the 
> same query concurrently and pin them to two different cores separately. However, 
> each execution time becomes 132 seconds in this case.

If the queries are fetching the exact same data, this seems unsurprising
--- you will have a lot of contention for page-level locks.  A more
realistic case would involve concurrent queries looking at different
data.  Perhaps overlapping sets of data, but not exactly the same data.
        regards, tom lane