Re: [HACKERS] Parallel Queries and PostGIS

2016-04-26 Thread Paul Ramsey
On Fri, Apr 22, 2016 at 11:44 AM, Stephen Frost wrote: > Paul, > > * Paul Ramsey (pram...@cleverelephant.ca) wrote: >> On Mon, Mar 28, 2016 at 9:45 AM, Stephen Frost wrote: >> > Would you agree that it'd be helpful to have for making the st_union() >> >

Re: [HACKERS] Parallel Queries and PostGIS

2016-04-22 Thread Stephen Frost
Paul, * Paul Ramsey (pram...@cleverelephant.ca) wrote: > On Mon, Mar 28, 2016 at 9:45 AM, Stephen Frost wrote: > > Would you agree that it'd be helpful to have for making the st_union() > > work better in parallel? > > For our particular situation w/ ST_Union, yes, it would

Re: [HACKERS] Parallel Queries and PostGIS

2016-04-12 Thread David Rowley
On 1 April 2016 at 17:12, David Rowley wrote: > On 30 March 2016 at 09:14, Robert Haas wrote: >> On Tue, Mar 29, 2016 at 3:48 PM, Paul Ramsey >> wrote: I have no idea why the cost adjustments that you need are

Re: [HACKERS] Parallel Queries and PostGIS

2016-03-31 Thread David Rowley
On 30 March 2016 at 09:14, Robert Haas wrote: > On Tue, Mar 29, 2016 at 3:48 PM, Paul Ramsey > wrote: >>> I have no idea why the cost adjustments that you need are different >>> for the scan case and the aggregate case. That does seem

Re: [HACKERS] Parallel Queries and PostGIS

2016-03-31 Thread Amit Kapila
On Fri, Apr 1, 2016 at 12:49 AM, Paul Ramsey wrote: > > On Tue, Mar 29, 2016 at 12:51 PM, Paul Ramsey wrote: > > On Tue, Mar 29, 2016 at 12:48 PM, Paul Ramsey wrote: > > > >>> On the join case, I wonder if it's

Re: [HACKERS] Parallel Queries and PostGIS

2016-03-31 Thread Paul Ramsey
On Tue, Mar 29, 2016 at 12:51 PM, Paul Ramsey wrote: > On Tue, Mar 29, 2016 at 12:48 PM, Paul Ramsey > wrote: > >>> On the join case, I wonder if it's possible that _st_intersects is not >>> marked parallel-safe? If that's not the problem,

Re: [HACKERS] Parallel Queries and PostGIS

2016-03-29 Thread Paul Ramsey
On Tue, Mar 29, 2016 at 1:14 PM, Robert Haas wrote: > On Tue, Mar 29, 2016 at 3:48 PM, Paul Ramsey > wrote: >>> I have no idea why the cost adjustments that you need are different >>> for the scan case and the aggregate case. That does seem

Re: [HACKERS] Parallel Queries and PostGIS

2016-03-29 Thread Robert Haas
On Tue, Mar 29, 2016 at 3:48 PM, Paul Ramsey wrote: >> I have no idea why the cost adjustments that you need are different >> for the scan case and the aggregate case. That does seem problematic, >> but I just don't know why it's happening. > > What might be a good way

Re: [HACKERS] Parallel Queries and PostGIS

2016-03-29 Thread Paul Ramsey
On Tue, Mar 29, 2016 at 12:48 PM, Paul Ramsey wrote: >> On the join case, I wonder if it's possible that _st_intersects is not >> marked parallel-safe? If that's not the problem, I don't have a >> second guess, but the thing to do would be to figure out whether >>

Re: [HACKERS] Parallel Queries and PostGIS

2016-03-29 Thread Paul Ramsey
> First, I beg to differ with this statement: "Some of the execution > results output are wrong! " The point is that > line has loops=4, so as in any other case where loops>1, you're seeing > the number of rows divided by the number of loops. It is the > *average* number of rows that were

Re: [HACKERS] Parallel Queries and PostGIS

2016-03-29 Thread Robert Haas
On Mon, Mar 28, 2016 at 12:18 PM, Paul Ramsey wrote: > I spent some time over the weekend trying out the different modes of > parallel query (seq scan, aggregate, join) in combination with PostGIS > and have written up the results here: > >

Re: [HACKERS] Parallel Queries and PostGIS

2016-03-29 Thread Paul Ramsey
On Mon, Mar 28, 2016 at 9:18 AM, Paul Ramsey wrote: > Parallel join would be a huge win, so some help/pointers on figuring > out why it's not coming into play when our gist operators are in > effect would be helpful. Robert, do you have any pointers on what I should

Re: [HACKERS] Parallel Queries and PostGIS

2016-03-28 Thread Paul Ramsey
On Mon, Mar 28, 2016 at 9:45 AM, Stephen Frost wrote: > Paul, > > * Paul Ramsey (pram...@cleverelephant.ca) wrote: >> I spent some time over the weekend trying out the different modes of >> parallel query (seq scan, aggregate, join) in combination with PostGIS >> and have

Re: [HACKERS] Parallel Queries and PostGIS

2016-03-28 Thread Stephen Frost
Paul, * Paul Ramsey (pram...@cleverelephant.ca) wrote: > I spent some time over the weekend trying out the different modes of > parallel query (seq scan, aggregate, join) in combination with PostGIS > and have written up the results here: > >

[HACKERS] Parallel Queries and PostGIS

2016-03-28 Thread Paul Ramsey
I spent some time over the weekend trying out the different modes of parallel query (seq scan, aggregate, join) in combination with PostGIS and have written up the results here: http://blog.cleverelephant.ca/2016/03/parallel-postgis.html The TL:DR; is basically * With some adjustments to