Re: Memory Accounting

On Mon, 2019-07-22 at 18:16 +0200, Tomas Vondra wrote:
> * I changed it to only update mem_allocated for the current
> > > context,
> > > not recursively for all parent contexts. It's now up to the
> > > function
> > > that reports memory usage to recurse or not (as needed).
> > 
> > Is that OK for memory bounded hash aggregation? Might there be a
> > lot 
> > of sub-contexts during hash aggregation?
> > 
> 
> There shouldn't be, at least not since b419865a814abbc. There might
> be
> cases where custom aggregates still do that, but I think that's
> simply a
> design we should discourage.

Right, I don't think memory-context-per-group is something we should
optimize for.

Discussion:
https://www.postgresql.org/message-id/3839201.Nfa2RvcheX%40techfox.foxi
https://www.postgresql.org/message-id/5334D7A5.2000907%40fuzzy.cz

Commit link:

https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=b419865a814abbca12bdd6eef6a3d5ed67f432e1

Regards,
    Jeff Davis