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

On Thu, Feb 14, 2019 at 12:40:10AM -0800, Andres Freund wrote:
> Hi,
> 
> On 2019-02-13 15:31:14 +0900, Kyotaro HORIGUCHI wrote:
> > Instead, I added an accounting(?) interface function.
> > 
> > | MemoryContextGettConsumption(MemoryContext cxt);
> > 
> > The API returns the current consumption in this memory
> > context. This allows "real" memory accounting almost without
> > overhead.
> 
> That's definitely *NOT* almost without overhead. This adds additional
> instructions to one postgres' hottest set of codepaths.
> 
> I think you're not working incrementally enough here. I strongly suggest
> solving the negative cache entry problem, and then incrementally go from
> there after that's committed. The likelihood of this patch ever getting
> merged otherwise seems extremely small.

Agreed --- the patch is going in the wrong direction.

-- 
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

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