Re: 9.2beta1, parallel queries, ReleasePredicateLocks, CheckForSerializableConflictIn in the oprofile

On Wed, May 30, 2012 at 3:15 PM, Jeff Janes <jeff(dot)janes(at)gmail(dot)com> wrote:
> On Wed, May 30, 2012 at 11:45 AM, Sergey Koposov <koposov(at)ast(dot)cam(dot)ac(dot)uk> wrote:
>> On Wed, 30 May 2012, Merlin Moncure wrote:
>>>
>>>
>>> Hm, why aren't we getting a IOS?  Just for kicks (assuming this is
>>> test data), can we drop the index on just transitid, leaving the index
>>> on transitid, healpixid?    Is enable_indexonlyscan on?  Has idt_match
>>> been vacuumed?  What kind of plan do you get when do:
>>
>>
>> Okay dropping the index on transitid solved the issue with indexonlyscan but
>> didn't solve the original problem. Actually the indexonlyscan made the
>> sequential queries faster but not the parallel ones.
>
> How big is idt_match?  What if you drop all indexes on idt_match,
> encouraging all the backends to do hash joins against it, which occur
> in local memory and so don't have contention?

You just missed his post -- it's only 3G. can you run your 'small'
working set against 48gb shared buffers?

merlin