3 ms·

“Tuned” how?

• deleted 3y ago
  [deleted]
• tomnipotent 3y ago
  The default "Postgres" uses: shared_buffers = 128MB max_parallel_workers = 8 max_parallel_workers_per_gather = 2 work_mem = 4MB "Postgres (tuned)" uses: shared_buffers = 8GB (64x the default) max_parallel_workers = 16 max_parallel_workers_per_gather = 8 work_mem = 4MB "Hydra" uses: shared_buffers = 8GB max_parallel_workers = 16 max_worker_processes = 32 (default 8) work_mem = 64MB The default settings are not realistic when running on a c6a.4xlarge instance, and the "Postgres (tuned)" settings more closely match what "Hydra" is configured to use. I consider it dishonest because I do not believe a team working this close to Postgres internals wouldn't know this.
  • _nvp 3y ago
    Yes, setting between Hydra and Postgres (tuned) are somehow aligned. But what Postgres (tuned) also creates are bunch of indexes (https://github.com/ClickHouse/ClickBench/blob/main/postgresql-tuned/index.sql https://github.com/ClickHouse/ClickBench/blob/main/postgresq...) which adds around ~50GB of extra storage.
    • tomnipotent 3y ago
      Equivalent settings makes the comparison more useful, and storage-conscious readers will pick-up that Postgres uses 4-6x more.
      • _nvp 3y ago
        Agree, but also, IMO, using index is what gives also performance boost. Just looking at queries that use string search - they have best result overall in complete test. Postgres (tuned) is designed for this specific clickbench table and nothing wrong with that.
    • riku_iki 3y ago
      > Yes, setting between Hydra and Postgres (tuned) are somehow aligned. very somehow, since Hydra essentially is allowed to use 4 times more CPU cores.
• rspijker 3y ago
  https://github.com/ClickHouse/ClickBench/blob/main/postgresql-tuned/benchmark.sh https://github.com/ClickHouse/ClickBench/blob/main/postgresq... basically larger buffers and more concurrent workers.