On 2015/11/12 14:09, Kouhei Kaigai wrote: > I'm now designing the parallel feature of Append... > > Here is one challenge. How do we determine whether each sub-plan > allows execution in the background worker context? > > The commit f0661c4e8c44c0ec7acd4ea7c82e85b265447398 added > 'parallel_aware' flag on Path and Plan structure. > It tells us whether the plan/path-node can perform by multiple > background worker processes concurrently, but also tells us > nothing whether the plan/path-node are safe to run on background > worker process context.
When I was looking at the recent parallelism related commits, I noticed a RelOptInfo.consider_parallel flag. That and the function set_rel_consider_parallel() may be of interest in this regard. set_append_rel_size() passes the parent's state of this flag down to child relations but I guess that's not what you're after. Thanks, Amit -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
