RE: Protect syscache from bloating with negative cache entries - Mailing list pgsql-hackers

From Tsunakawa, Takayuki
Subject RE: Protect syscache from bloating with negative cache entries
Date
Msg-id 0A3221C70F24FB45833433255569204D1FB6D1A4@G01JPEXMBYT05
Whole thread Raw
In response to Re: Protect syscache from bloating with negative cache entries  (Kyotaro HORIGUCHI <horiguchi.kyotaro@lab.ntt.co.jp>)
List pgsql-hackers
From: Kyotaro HORIGUCHI [mailto:horiguchi.kyotaro@lab.ntt.co.jp]
> Although this doesn't put a hard cap on memory usage, it is indirectly and
> softly limited by the cache_prune_min_age and cache_memory_target, which
> determins how large a cache can grow until pruning happens. They are
> per-cache basis.
> 
> If we prefer to set a budget on all the syschaches (or even including other
> caches), it would be more complex.
> 

This is a pure question.  How can we answer these questions from users?

* What value can I set to cache_memory_target when I can use 10 GB for the caches and max_connections = 100?
* How much RAM do I need to have for the caches when I set cache_memory_target = 1M?

The user tends to estimate memory to avoid OOM.


Regards
Takayuki Tsunakawa





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