Re: Memory-Bounded Hash Aggregation - Mailing list pgsql-hackers

From Adam Lee
Subject Re: Memory-Bounded Hash Aggregation
Date
Msg-id 20200220040437.GA4389@earth.local
Whole thread Raw
In response to Re: Memory-Bounded Hash Aggregation  (Tomas Vondra <tomas.vondra@2ndquadrant.com>)
List pgsql-hackers
On Wed, Feb 19, 2020 at 08:16:36PM +0100, Tomas Vondra wrote:
> 4) lookup_hash_entries says
> 
>   /* check to see if we need to spill the tuple for this grouping set */
> 
> But that seems bogus, because AFAIK we can't spill tuples for grouping
> sets. So maybe this should say just "grouping"?

As I see it, it does traverse all hash sets, fill the hash table and
spill if needed, for each tuple.

The segfault is probably related to this and MixedAggregate, I'm looking
into it.

-- 
Adam Lee



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