Re: Finding out why parallel queries not avoided

2018-07-22 Thread Didier Carlier
> On 22 Jul 2018, at 05:45, David Rowley wrote: > > On 21 July 2018 at 20:15, Didier Carlier wrote: >> explain select count(*) from calendar c1, calendar c2, measure m where >> c1.stddate='2015-01-01' and c2.stddate='2015-12-31' and m.fromdateid

Finding out why parallel queries not avoided

2018-07-21 Thread Didier Carlier
I’m trying to find out why parallel queries are sometimes not used. For example, I have 2 tables, calendar (1 row per day, ~3K rows) and measure (~300M rows) which includes a FK to calendar. I.e knowing two day numbers, I can find out how many measures there are between these two dates with a