Hi Andrey, On Mon, Jun 1, 2020 at 6:29 PM Andrey Lepikhov <a.lepik...@postgrespro.ru> wrote: > Currently i see, COPY FROM insertion into the partitioned table with > foreign partitions is not optimal: even if table constraints allows can > do multi insert copy, we will flush the buffers and prepare new INSERT > query for each tuple, routed into the foreign partition. > To solve this problem i tried to use the multi insert buffers for > foreign tuples too. Flushing of these buffers performs by the analogy > with 'COPY .. FROM STDIN' machinery as it is done by the psql '\copy' > command. > The patch in attachment was prepared from the private scratch developed > by Arseny Sher a couple of years ago. > Benchmarks shows that it speeds up COPY FROM operation: > Command "COPY pgbench_accounts FROM ..." (test file contains 1e7 tuples, > copy to three partitions) executes on my laptop in 14 minutes without > the patch and in 1.5 minutes with the patch. Theoretical minimum here > (with infinite buffer size) is 40 seconds.
Great! > A couple of questions: > 1. Can this feature be interesting for the PostgreSQL core or not? Yeah, I think this is especially useful for sharding. > 2. If this is a useful feature, is the correct way chosen? I think I also thought something similar to this before [1]. Will take a look. Thanks! Best regards, Etsuro Fujita [1] https://www.postgresql.org/message-id/23990375-45a6-5823-b0aa-a6a7a6a957f0%40lab.ntt.co.jp
