Re: Postgres process count GCC vs Clang is Different on autovaccum=on

On 11/24/21 13:05, hpc researcher_mspk wrote:
> Software/Hardware used:
> ===================
> PostgresV14.v
> OS: RHELv8.4
> Benchmark:HammerDB v4.3
> Hardware used: Apple/AMD Ryzen.
> RAM size: 256 GB
> SSD/HDD: 1TB
> CPU(s): 256(0-255)
> Thread(s) per core:  2
> Core(s) per socket:  64
> Socket(s):           2
> NUMA node(s):        8
> 
> Command used to count process: ps -eaf | grep postgres
> 
> Case1: AutoVaccum=on
> vu    GCC    Clang
> 32    43    42
> 64    76    74
> 192    203    202
> 250    262    262
> 
> 
> Case2:AutoVaccum=off
> vu    GCC    Clang
> 32    40    40
> 64    72    72
> 192    200    200
> 250    261    263
> 
> 
> In Case1 why is the process different in Clang vs GCC.
> In postgresql process dependent wrt compiler GCC/Clang?

No, it's not. The most likely explanation is that you're seeing 
different number of autovacuum workers. Those are dynamic, i.e. may 
appear/disappear. Or maybe there are more connections to the DB.


regards

-- 
Tomas Vondra
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company