It sounds strange but the "type" is indeed impacting the overall performance somehow. I've just tried to execute the following sequence of commands on a fresh new database with PostreSQL v10 and both the copy and primary key commands performed as slow as in v11 and 12.
SET synchronous_commit TO OFF; SET client_encoding TO 'UTF8'; COPY ways FROM program 'cmd /c "type D:\ways.txt"'; ALTER TABLE ONLY ways ADD CONSTRAINT pk_ways PRIMARY KEY (id); Regards пт, 29 нояб. 2019 г. в 15:22, Eugene Podshivalov <yauge...@gmail.com>: > > Laurenz, > There is no way to run copy without the "type" on v11. See this thread > https://www.postgresql.org/message-id/CAKHmqNCfTMM6%3DPqc6RUMEQ_2BPfo5KGGG-0fzRXZCVooo%3DwdNA%40mail.gmail.com > > My machine is running on NVMe disks, so the I/O subsystem very strong. > The 100% overload is not constant but periodical, as if there are some > kind of dumps for recovery performed in the background. > > maintenance_work_mem is the same in both cases. > > Regards > > пт, 29 нояб. 2019 г. в 15:04, Laurenz Albe <laurenz.a...@cybertec.at>: > > > > On Fri, 2019-11-29 at 13:04 +0300, Eugene Podshivalov wrote: > > > I'm using PostgreSQL on Windows for Planet OSM database and have > > > noticed considirable decrease in performance when upgrading from v10 > > > to 11 or 12. Here are the details of the experiment I conducted trying > > > to figure out what is causing the issue. > > > > > > Installed PostgreSQL 10 from scratch. Created a database and a table. > > > [...] > > > SET synchronous_commit TO OFF; > > > COPY ways FROM 'E:\ways.txt'; > > > ALTER TABLE ONLY ways ADD CONSTRAINT pk_ways PRIMARY KEY (id); > > > > > > The file is 365GB in size. > > > > > > The copy operation took 3.5h and the resulting table size is 253GB. > > > The primary key operation took 20 minutes and occuped 13GB of disk > > > space. > > > > > > Then I unstalled PostgreSQL v10, deleted the data directory and > > > installed v11 from scratch. Created the same kind of database and > > > table. v11 is not able to handle large files, so the I piped the data > > > through the cmd type command, and then added the primary key with the > > > same command as above. synchronous_commit turned off beforehand as > > > above. > > > > > > COPY ways FROM PROGRAM 'cmd /c "type E:\ways.txt"'; > > > > > > The copy operation took 7 hours and adding primary key took 1h 40m ! > > > The resulting table and pk sizes are the same as in v10. Also very > > > high load on disk drive (quite often at 100%) was observed. > > > > > > v12 performs the same as v11. > > > > > > Here are the changes in v11 default postgresql.conf file compared to > > > v10 one. Differences in Authentication, Replication and Logging > > > sections are skipped. > > > > > > -#replacement_sort_tuples = 150000 > > > +#max_parallel_maintenance_workers = 2 > > > +#parallel_leader_participation = on > > > ~max_wal_size = 1GB (in v10 is commented out) > > > ~min_wal_size = 80MB (in v10 is commented out) > > > +#enable_parallel_append = on > > > +#enable_partitionwise_join = off > > > +#enable_partitionwise_aggregate = off > > > +#enable_parallel_hash = on > > > +#enable_partition_pruning = on > > > +#jit_above_cost = 100000 > > > +#jit_inline_above_cost = 500000 > > > +#jit_optimize_above_cost = 500000 > > > +#jit = off > > > +#jit_provider = 'llvmjit' > > > +#vacuum_cleanup_index_scale_factor = 0.1 > > > > > > Any ideas pleaes on what is trapping the performance? > > > > Seems like you have a very weak I/O subsystem. > > > > For the COPY, try doing it the same way in both cases (without the "type"). > > > > For the index creation, perhaps set "max_parallel_maintenance_workers = 0" > > so that your system doesn't get overloaded. > > > > Is "maintenance_work_mem" set to the same value in both cases? > > > > Yours, > > Laurenz Albe > > -- > > Cybertec | https://www.cybertec-postgresql.com > >
