Re: [HACKERS] Moving relation extension locks out of heavyweight lock manager

On Tue, Jun 26, 2018 at 12:47 PM Masahiko Sawada <sawada.mshk@gmail.com> wrote:
>
> Type of table: normal table, unlogged table
> Number of child tables : 16, 64 (all tables are located on the same tablespace)
> Number of clients : 32
> Number of trials : 100
> Duration: 180 seconds for each trials
>
> The hardware spec of server is Intel Xeon 2.4GHz (HT 160cores), 256GB
> RAM, NVMe SSD 1.5TB.
> Each clients load 10kB random data across all partitioned tables.
>
> Here is the result.
>
>  childs |   type   | target  |  avg_tps   | diff with HEAD
> --------+----------+---------+------------+------------------
>      16 | normal   | HEAD    |   1643.833 |
>      16 | normal   | Patched |  1619.5404 |      0.985222
>      16 | unlogged | HEAD    |  9069.3543 |
>      16 | unlogged | Patched |  9368.0263 |      1.032932
>      64 | normal   | HEAD    |   1598.698 |
>      64 | normal   | Patched |  1587.5906 |      0.993052
>      64 | unlogged | HEAD    |  9629.7315 |
>      64 | unlogged | Patched | 10208.2196 |      1.060073
> (8 rows)
>
> For normal tables, loading tps decreased 1% ~ 2% with this patch
> whereas it increased 3% ~ 6% for unlogged tables. There were
> collisions at 0 ~ 5 relation extension lock slots between 2 relations
> in the 64 child tables case but it didn't seem to affect the tps.
>

How did you measure the collisions in this test?  I think it is better
if Mahendra can also use the same technique in measuring that count.

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