On 12 April 2016 at 07:58, Amit Kapila <amit.kapil...@gmail.com> wrote:
> On Tue, Apr 12, 2016 at 3:15 AM, Simon Riggs <si...@2ndquadrant.com> > wrote: > >> On 8 April 2016 at 17:49, Robert Haas <robertmh...@gmail.com> wrote: >> >> >>> With the patch, you can - if you wish - substitute >>> some other number for the one the planner comes up with. >> >> >> I saw you're using AccessExclusiveLock, the reason being it affects >> SELECTs. >> >> That is supposed to apply when things might change the answer from a >> SELECT, whereas this affects only the default for a plan. >> >> > By this theory, shouldn't any other parameter like n_distinct_inherited > which just effects the plan required lower lock level? > It should, yes, and I'm as surprised to see it isn't as you are. Thread: Fabrizio was asked by Robert to provide or document an analysis of why each setting was OK to change; 9 days later he had not done so or replied, so I committed a reduced version of the patch that matched existing tests and code comments. I guess we could have salvaged some more from it, but we didn't and there's never enough time. If RMT allows, that can be changed or it can wait. -- Simon Riggs http://www.2ndQuadrant.com/ <http://www.2ndquadrant.com/> PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
