Re: pg_dump from v13 is slow

2020-08-13 Thread Tom Lane
Justin Pryzby writes: > I can reproduce the issue with generated data: > pryzbyj=# SELECT format('create table t%s(i int)', i) FROM > generate_series(1,)i; Hm, I tried this case and didn't really detect much runtime difference between v12 and HEAD. > I don't know if it's any issue, but I

Re: pg_dump from v13 is slow

2020-08-13 Thread Justin Pryzby
On Thu, Aug 13, 2020 at 08:53:46PM -0400, Alvaro Herrera wrote: > Hmm, I wonder if you're comparing an assert-enabled pg13 build to a > non-assert-enabled pg12 build, or something like that. Great question - I thought of it myself but then forgot to look.. $ rpm -q postgresql1{2,3}-server

Re: pg_dump from v13 is slow

2020-08-13 Thread Alvaro Herrera
Hmm, I wonder if you're comparing an assert-enabled pg13 build to a non-assert-enabled pg12 build, or something like that. -- Álvaro Herrerahttps://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Re: pg_dump from v13 is slow

2020-08-13 Thread Justin Pryzby
I can reproduce the issue with generated data: pryzbyj=# SELECT format('create table t%s(i int)', i) FROM generate_series(1,)i; \set ECHO errors \set QUIET \gexec $ time pg_dump --section=pre-data -d pryzbyj -h /tmp -p 5613 |wc 110015 240049 1577087 real0m50.445s $ time pg_dump

Re: pg_dump from v13 is slow

2020-08-13 Thread Andres Freund
Hi, On 2020-08-13 17:48:23 -0500, Justin Pryzby wrote: > I'm trying to narrow this down, but I'd be very happy for suggestions. Would be worth knowing how much of the time pgbench is 100% CPU utilized, and how much of the time it is basically waiting for server side queries and largely idle. If

Re: pg_dump from v13 is slow

2020-08-13 Thread Alvaro Herrera
On 2020-Aug-13, Justin Pryzby wrote: > I'm trying to narrow this down, but I'd be very happy for suggestions. Maybe you can time "pg_dump --binary-upgrade" to see if the slowness comes from there. -- Álvaro Herrerahttps://www.2ndQuadrant.com/ PostgreSQL Development, 24x7

pg_dump from v13 is slow

2020-08-13 Thread Justin Pryzby
I ran into this while running pg_upgrade from beta2 to beta3: $ time sudo -u postgres sh -c 'cd /var/lib/pgsql; /usr/pgsql-13/bin/pg_upgrade -b /usr/pgsql-13b2/bin/ -d ./13b2/data -D ./13/data --link' real94m18.335s This instances has many table partitions, and the production