Hi,
On 2016/10/05 14:19, Chenxi Li wrote:
> Hello,
>
> I'm reading some papers about aggregation push down like in "
> https://ub-madoc.bib.uni-mannheim.de/37228/1/main.pdf; and "
> http://www.vldb.org/conf/1995/P345.PDF;. I think it is very useful but very
> complex to implement. In some complex queries, it can be a lot faster. Is
> there any plan to do this in the future?
Thanks for the links. On a quick look, I think you are referring to the
following section in the document at the first link (and the title of the
paper at the second link):
4.2 Applying Eager Aggregation
I think someone is working on something like that. Check out the
following discussion (currently inactive though):
* Partial Aggregation / GROUP BY before JOIN *
https://www.postgresql.org/message-id/flat/CAKJS1f9kw95K2pnCKAoPmNw%3D%3D7fgjSjC-82cy1RB%2B-x-Jz0QHA%40mail.gmail.com
There is also related work which is under active development:
* Aggregate Push Down - Performing aggregation on foreign server *
https://www.postgresql.org/message-id/flat/CAM2%2B6%3DW%3Dr_vh2gpccPJ4tc%3D%2BhFm4UGQsQdZgt4GiBMYVEk%2B5vg%40mail.gmail.com
In this case, the aggregation step is pushed all the way to the remote
server where the data resides. It stands to avoid a good deal of
unnecessary data traffic across the network.
Thanks,
Amit
--
Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers
