Horton

Re: Speed up Clog Access by increasing CLOG buffers

Amit Kapila <amit.kapila16@gmail.com>

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From: Amit Kapila <amit.kapila16@gmail.com>
To: Andres Freund <andres@anarazel.de>
Cc: pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2016-04-07T13:10:14Z
Lists: pgsql-hackers 
On Thu, Apr 7, 2016 at 10:16 AM, Andres Freund <andres@anarazel.de> wrote:
>
> 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?
>

This is the data with -b tpcb-like@1 with 20-min run for each version and I
could see almost similar results as the data posted in previous e-mail.

Client Count/Patch_ver (tps) 256
clog_buf_128 40617
clog_buf_128 +group_clog_v8 51137
clog_buf_128 +content_lock 54188

For -b select-only@3,  I have done quicktest for each version and number is
same 62K~63K for all version, why do you think this will improve
select-only workload?


With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com

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.