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

On Tue, Jun 26, 2018 at 12:47 PM Masahiko Sawada <sawada(dot)mshk(at)gmail(dot)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