[Linuxppc-users] PostgreSQL support on IBM Power Systems

[Toshaan Bharvani | VanTosh]

Daniel,

On 04/09/2019 06:08, Daniel Black wrote:
> On Tue, 3 Sep 2019 17:51:34 +0200
> Toshaan Bharvani | VanTosh <toshaan at vantosh.com> wrote:
> 
>> Yasal,
>>
>>
>> On 29/08/2019 14:50, Yasal Akgun wrote:
>>> Hi,
>>>
>>> Do you have references for postgresql running on Power (LPAR or
>>> full-dedicated)?  
>>
>> We have multiple instances of PostgreSQL v10 and v11, all on Linux ppc64
>> and ppc64le. We run this for multiple of our customers.
>> All are running in Linux KVM Qemu virtual machines.
>> We also have x86_64 to compare with
> 
> 
> Nice!
> 
> A while ago was helping someone out with a potential customer that showed a CPU large usage in postgresql's PinBuffer function but never really got to the bottom of it without a reproducible load with easy access (and whether this was general postgresql tuning problem).
Yes, I remember having problems with CPU and memory usage inconsistency,
this was on a v8 and v9.5 and lower, once we moved to v9.6 all problems
seem to have been solved.


> 
> So while you have access to multiple instances, are there Postgresql functions that show a higher CPU usage in POWER compared to x86 that I could look optimizing (ahead of potential clients asking)? If so can you show a test case to show it?
The only functions/queries we see slower on POWER is the full text
search , a WHERE LIKE query or tsvector/tsquery function normally does
very well, however in some cases, we have seen increased CPU and slower
responses.
Unfortunately, we have difficulty reproducing theses, so I haven't filed
any reports, as we do not really understand where the issue could be and
if it is actually even a Pg issue and not a query issue.


> 
> Performance data gather with:
> 
> perf record -g ; perf report -g --no-children --stdio
> 
> Coincidently I'm meeting with 2 postgresql developers next week where I could discuss improvements.
> 
I will send you some data by end of the week.
If you are working on tests and other improvements, we can always talk
offline or I can assist with testing, we have multiple architectures.


Regards,
Toshaan.

-- 
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Toshaan Bharvani
+32-(0)476-66.70.55
toshaan at vantosh.com
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