Horton

Re: Speed up Clog Access by increasing CLOG buffers

Jesper Pedersen <jesper.pedersen@redhat.com>

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From: Jesper Pedersen <jesper.pedersen@redhat.com>
To: Andres Freund <andres@anarazel.de>
Cc: Amit Kapila <amit.kapila16@gmail.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2016-04-01T20:25:51Z
Lists: pgsql-hackers 
Hi,

On 03/31/2016 06:21 PM, Andres Freund wrote:
> On March 31, 2016 11:13:46 PM GMT+02:00, Jesper Pedersen <jesper.pedersen@redhat.com> wrote:
>
>> I can do a USE_CONTENT_LOCK run on 0003 if it is something for 9.6.
>
> Yes please. I think the lock variant is realistic, the lockless did isn't.
>

I have done a run with -M prepared on unlogged running 10min per data 
point, up to 300 connections. Using data + wal on HDD.

I'm not seeing a difference between with and without USE_CONTENT_LOCK -- 
all points are within +/- 0.5%.

Let me know if there are other tests I can perform.

Best regards,
  Jesper

Commits

  1. Use group updates when setting transaction status in clog.

  2. Improve 64bit atomics support.

  3. Add ProcArrayGroupUpdate wait event.

  4. Make the different Unix-y semaphore implementations ABI-compatible.

  5. Fix broken ALTER INDEX documentation

  6. Code and docs review for commit 3187d6de0e5a9e805b27c48437897e8c39071d45.

  7. Partition the freelist for shared dynahash tables.

  8. Correct StartupSUBTRANS for page wraparound

  9. Make idle backends exit if the postmaster dies.

  10. contrib/sslinfo: add ssl_extension_info SRF

  11. Reduce ProcArrayLock contention by removing backends in batches.

  12. Fix `make installcheck` for serializable transactions.

  13. Lockless StrategyGetBuffer clock sweep hot path.

  14. Reduce sinval synchronization overhead.