Re: Relation extension scalability

On Thu, Mar 31, 2016 at 4:28 PM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:

> Yeah, kind of. But obviously if we could make the limit smaller
> without hurting performance, that would be better.
>
> Per my note yesterday about performance degradation with parallel
> COPY, I wasn't able to demonstrate that this patch gives a consistent
> performance benefit on hydra - the best result I got was speeding up a
> 9.5 minute load to 8 minutes where linear scalability would have been
> 2 minutes. And I found cases where it was actually slower with the
> patch. Now maybe hydra is just a crap machine, but I'm feeling
> nervous.
>

I see the performance gain when either
"*complete data is in SSD*"
or *"data on MD and WAL on SSD"*
or *unlogged table*.

What machines did you use to test this? Have you tested really large
> data loads, like many MB or even GB of data?
>

With INSERT Script within 2 mins run data size is 18GB I am running 5-10
Mins means at least 85GB data.
(Inserts 1000 1KB tuples in each transactions)

With COPY Script within 2 mins run data size is 23GB and I am running 5-10
Mins means at least 100GB data.
(Inserts 10000 tuples in each transactions (tuple size is 1byte to 5 bytes)

Machine Details
-----------------------
I tested in 8 socket NUMA machine with 64 core.
Machine Details:
----------------------
[dilip(dot)kumar(at)cthulhu ~]$ lscpu
Architecture: x86_64
CPU op-mode(s): 32-bit, 64-bit
Byte Order: Little Endian
CPU(s): 128
On-line CPU(s) list: 0-127
Thread(s) per core: 2
Core(s) per socket: 8
Socket(s): 8
NUMA node(s): 8
Vendor ID: GenuineIntel
CPU family: 6
Model: 47
Model name: Intel(R) Xeon(R) CPU E7- 8830 @ 2.13GHz
Stepping: 2
CPU MHz: 1064.000
BogoMIPS: 4266.62

If you need some more information please let me know ?

--
Regards,
Dilip Kumar
EnterpriseDB: http://www.enterprisedb.com