On 4 April 2018 at 07:46, Justin Pryzby <pryzby@telsasoft.com> wrote:
> TLDR: even with "faster pruning" patch, pg11dev open()+lseek() every file
> backing every table being queried, even for those partitions eventually
> "excluded".
Yeah, this will no doubt be due to the fact that we still build
RelOptInfos in the planner for all partitions, so we're still doing
get_relation_info() and estimate_rel_size() for each of those. It
might be possible to delay that call until we know we're going to need
the partition. I imagine we wouldn't need to know the size of the
relation until after set_rel_sizes, but I've not checked.
--
David Rowley http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services