Re: effective_cache_size cfg

>
> On Oct 15, 2018, at 12:04 PM, Ghiurea, Isabella <Isabella.Ghiurea@nrc-cnrc.gc.ca> wrote:
>
> I am running PGSQL 10.4  on Cent OS  Pg instance has ' effective_cache_size' parameter not  enabled I would like to
learnwhat will  the optimizer behavior be in this case ? 
>  ( default is set to 4GB , I was  thinking  PG 's optimizer will try to use all available OS RAM when trying to
estimatea query, is this the case) 

That's merely a hint to the optimizer as to how much file data is likely to be cached by the OS--it doesn't directly
affectany PG allocations, rather it might influence PG's choice of steps to carry out a query, which of course could
indirectlychange the RAM that PG would use. 

--
Scott Ribe
scott_ribe@elevated-dev.com
https://www.linkedin.com/in/scottribe/