Horton

Re: Speed up Clog Access by increasing CLOG buffers

Andres Freund <andres@anarazel.de>

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From: Andres Freund <andres@anarazel.de>
To: Amit Kapila <amit.kapila16@gmail.com>
Cc: pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2016-04-07T04:46:16Z
Lists: pgsql-hackers 
Hi,

On 2016-04-07 09:14:00 +0530, Amit Kapila wrote:
> On Sat, Apr 2, 2016 at 5:25 PM, Amit Kapila <amit.kapila16@gmail.com> wrote:
> I have ran exactly same test on intel x86 m/c and the results are as below:

Thanks for running these tests!

> Client Count/Patch_ver (tps) 2 128 256
> HEAD – Commit 2143f5e1 2832 35001 26756
> clog_buf_128 2909 50685 40998
> clog_buf_128 +group_update_clog_v8 2981 53043 50779
> clog_buf_128 +content_lock 2843 56261 54059
> clog_buf_128 +nocontent_lock 2630 56554 54429

Interesting.

could you perhaps also run a test with -btpcb-like@1 -bselect-only@3?
That much represents real world loads, and it's where I saw simon's
approach outshining yours considerably...

Greetings,

Andres Freund

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.