Re: POC: Lock updated tuples in tuple_update() and tuple_delete()

Hi, hackers!
I ran the following benchmark on master branch (15) vs patch (15-lock):

On the 36-vcore AWS server, I've run an UPDATE-only pgbench script with 50
connections on pgbench_tellers with 100 rows. The idea was to introduce as
much as possible concurrency for updates but avoid much clients being in a
wait state.
Indexes were not built to avoid index-update-related delays.
Done 2 runs each consisting of 6 series of updates (1st run:
master-patch-master-patch-master-patch, 2nd run
patch-master-patch-master-patch-master)
Each series started a fresh server and did VACUUM FULL to avoid bloating
heap relation after the previous series to affect the current. It collected
data for 10 minutes with first-minute data being dropped.
Disk-related operations were suppressed where possible (WAL, fsync etc.)

postgresql.conf:
fsync = off
autovacuum = off
full_page_writes = off
max_worker_processes = 99
max_parallel_workers = 99
max_connections = 100
shared_buffers = 4096MB
work_mem = 50MB

Attached are pictures of 2 runs, shell script, and SQL script that were
running.
According to htop all 36-cores were loaded to ~94% in each series

I'm not sure how to interpret the results. Seems like a TPS difference
between runs is significant, with average performance with lock-patch *(15lock)
*seeming a little bit faster than the master* (15)*.

Could someone try to repeat this on another server? What do you think?

--
Best regards,
Pavel Borisov,
Supabase, https://supabase.com/