On 2015-05-14 02:51:42 -0400, Noah Misch wrote:
> Covering hash aggregation might entail a large preparatory refactoring
> of nodeHash.c, but beyond development cost I can't malign that.
You mean execGrouping.c? Afaics nodeHash.c isn't involved, and it
doesn't look very interesting to make it so?
Isn't that just calling BuildTupleHashTable() for each
to-be-hash-aggregated set, and then make agg_fill_hash_table() target
multiple hashtables? This mostly seems to be adding a couple loops and
parameters.
Greetings,
Andres Freund