Re: Why is Postgres only using 8 cores for partitioned count? [Parallel Append]

2021-02-14 Thread Seamus Abshere
Hi David, That is a great suggestion, except my partitions are foreign tables. I wonder if I could figure out a single empty partition that’s just a normal table... but I’m using hash partitioning, so I think I would lose a modulus. Best, Seamus -- Seamus Abshere, SCEA +1 (608) 772-0696 https

700% faster (was: Re: Why is Postgres only using 8 cores for partitioned count? [Parallel append])

2021-02-14 Thread Seamus Abshere
Best, Seamus PS. The awesome thing about this is that I'm table scanning a 270 million row, 600 column table in 1.2 seconds, which I never thought was possible. PPS. I have no idea why 96 worked better than 64 (the number of cores I have), but it did - 700% vs 400%. On Sat, Feb 13, 2021, at 7:09

Re: Why is Postgres only using 8 cores for partitioned count? [Parallel Append]

2021-02-13 Thread Seamus Abshere
for transaction cost). So why doesn't it ask for more? Note that I've set max_parallel_workers=512, etc. (postgresql.conf in my first message). Here are full plans https://gist.github.com/seamusabshere/1c1d869ee24145689f45e4124d8730d3 Best, Seamus On Fri, Feb 12, 2021, at 4:50 PM, Seamus Abshere wrote

Why is Postgres only using 8 cores for partitioned count?

2021-02-13 Thread Seamus Abshere
max_wal_size = 4GB max_worker_processes = 512 min_wal_size = 1GB random_page_cost = 1.1 shared_buffers = 127232MB shared_preload_libraries = 'cstore_fdw' synchronous_commit=off wal_buffers = 16MB work_mem = 1628560kB Best, Seamus -- Seamus Abshere, SCEA https://faraday.ai https://github.com/seamusabshere

Too many BitmapAnds in the wild

2018-09-17 Thread Seamus Abshere
essage-id/flat/CAMkU%3D1yV7WQLetrCVPqn%3DdTPdNzW3JD29ZsK0zJmgzO2tdcx-Q%40mail.gmail.com#aa3b3316cbe44fb3fd913ce019a86bb8 [2] https://github.com/postgres/postgres/blame/master/src/backend/optimizer/path/costsize.c#L1056 -- Seamus Abshere, SCEA +598 9954 9954 https://www.faraday.io https://gith

warning for subquery that references a table but not its columns

2018-01-18 Thread Seamus Abshere
l from subscribed where email not in (select tracks.ema... (the "tracks" table doesn't have an "email" column, so the first query is just meaningless) Should there be a warning for the first query that you reference "tracks" in a subquery but don't use any columns fro