On Tue, Mar 10, 2015 at 10:23 AM, Haribabu Kommi <kommi.harib...@gmail.com> wrote: > > On Tue, Mar 10, 2015 at 3:09 PM, Amit Kapila <amit.kapil...@gmail.com> wrote: > > > I have currently modelled it based on existing rescan for seqscan > > (ExecReScanSeqScan()) which means it will begin the scan again. > > Basically if the workers are already started/initialized by previous > > scan, then re-initialize them (refer function ExecReScanFunnel() in > > patch). > > > > Can you elaborate more if you think current handling is not sufficient > > for any case? > > From ExecReScanFunnel function it seems that the re-scan waits till > all the workers > has to be finished to start again the next scan. Are the workers will > stop the current > ongoing task? otherwise this may decrease the performance instead of > improving as i feel. >
Okay, performance-wise it might effect such a case, but I think we can handle it by not calling WaitForParallelWorkersToFinish(), as DestroyParallelContext() will automatically terminate all the workers. > I am not sure if it already handled or not, when a worker is waiting > to pass the results, > whereas the backend is trying to start the re-scan? > I think stopping/terminating workers should handle such a case. Thanks for pointing out this case, I will change it in next update. With Regards, Amit Kapila. EnterpriseDB: http://www.enterprisedb.com
