Thread added to TODO for item:
* Allow sequential scans to take advantage of other concurrent
sequential scans, also called "Synchronised Scanning"
---
Jeff Davis wrote:
> I have updated my Synchronized Scan patch and ha
On Tue, Jan 02, 2007 at 09:48:22AM -0800, Jeff Davis wrote:
> On Sat, 2006-12-30 at 13:35 -0600, Jim C. Nasby wrote:
> > > My current implementation relies on the scans to stay close together
> > > once they start close together. If one falls seriously behind, it will
> > > fall outside of the main
On Sat, 2006-12-30 at 13:35 -0600, Jim C. Nasby wrote:
> > My current implementation relies on the scans to stay close together
> > once they start close together. If one falls seriously behind, it will
> > fall outside of the main "cache trail" and cause the performance to
> > degrade due to disk
On Tue, Dec 19, 2006 at 10:37:21AM -0800, Jeff Davis wrote:
> > leader is doing a nested loop and the follower which is just doing a
> > straight
> > sequential scan is being held back?
> >
>
> The follower will never be held back in my current implementation.
>
> My current implementation reli
On Tue, 2006-12-19 at 18:05 +, Gregory Stark wrote:
> "Simon Riggs" <[EMAIL PROTECTED]> writes:
>
> > Like to see some tests with 2 parallel threads, since that is the most
> > common case. I'd also like to see some tests with varying queries,
> > rather than all use select count(*). My worry
"Simon Riggs" <[EMAIL PROTECTED]> writes:
> Like to see some tests with 2 parallel threads, since that is the most
> common case. I'd also like to see some tests with varying queries,
> rather than all use select count(*). My worry is that these tests all
> progress along their scans at exactly th
On Tue, 2006-12-19 at 17:43 +, Simon Riggs wrote:
> On Tue, 2006-12-19 at 09:07 -0800, Jeff Davis wrote:
> > I have updated my Synchronized Scan patch and have had more time for
> > testing.
> >
> > Go to http://j-davis.com/postgresql/syncscan-results10.html
> > where you can download the patc
On Tue, 2006-12-19 at 09:07 -0800, Jeff Davis wrote:
> I have updated my Synchronized Scan patch and have had more time for
> testing.
>
> Go to http://j-davis.com/postgresql/syncscan-results10.html
> where you can download the patch, and see the benchmarks that I've run.
>
> The results are very
I have updated my Synchronized Scan patch and have had more time for
testing.
Go to http://j-davis.com/postgresql/syncscan-results10.html
where you can download the patch, and see the benchmarks that I've run.
The results are very promising. I did not see any significant slowdown
for non-concurre
