Hi Robert, Generally, a subsystem can avoid needing a callback at subtransaction > start (or transaction start) by detecting new levels of > subtransactions at time of use.
Yes I agree with this argument. > A typical practice is to maintain a > stack which has entries only for those transaction nesting levels > where the functionality was used. The attached patch implements this > method for async.c. I have reviewed your patch, and it seems correctly implementing the actions per subtransactions using stack. Atleast I could not find any flaw with your implementation here. > I was a little surprised to find that it makes a > pretty noticeable performance difference when starting and ending > trivial subtransactions. I used this test case: > > \timing > do $$begin for i in 1 .. 10000000 loop begin null; exception when > others then null; end; end loop; end;$$; > I ran your testcase and on my VM I get numbers like 3593.801 ms without patch and 3593.801 with the patch, average of 5 runs each. The runs were quite consistent. Further make check also passing well. Regards, Jeevan Ladhe
