On Thu, Nov 18, 2021 at 1:18 PM Robert Creager <robertc@xxxxxxxxxxxxxxxx> wrote: > So, how do I go about capturing more information for the big brains (you guys) to help figure this out? I have all our resources at mine (and hence your) disposal. As a workaround, does it help if you issue DISCARD PLANS before your COPY jobs, or alternatively start with a fresh connection? I'm guessing that something like this is happening. -- set up the auto_explain extension to show the internal foreign key check queries' plans load 'auto_explain'; set auto_explain.log_nested_statements = true; set auto_explain.log_min_duration = 0; set auto_explain.log_analyze = true; drop table if exists r, s cascade; create table r (i int primary key); create table s (i int references r(i)); -- collect stats showing r as empty analyze r; -- execute RI query 6 times to lock the plan (inserts fail, log shows seq scan) insert into s values (42); insert into s values (42); insert into s values (42); insert into s values (42); insert into s values (42); insert into s values (42); insert into r select generate_series(1, 1000000); -- once more, we still get a seq scan, which is by now a bad idea insert into s values (42); discard plans; -- once more, now we get an index scan insert into s values (42);
