On vendredi 24 mars 2017 08:14:03 CEST Ashutosh Bapat wrote: > On Mon, Mar 20, 2017 at 8:33 PM, Ronan Dunklau <ronan.dunk...@dalibo.com> wrote: > > On lundi 20 mars 2017 15:52:03 CET Robert Haas wrote: > >> On Mon, Mar 20, 2017 at 6:31 AM, Ronan Dunklau <ronan.dunk...@dalibo.com> > > > > wrote: > >> > With range partitioning, we guarantee that each partition contains non- > >> > overlapping values. Since we know the range allowed for each partition, > >> > it > >> > is possible to sort them according to the partition key (as is done > >> > already for looking up partitions). > >> > > >> > Thus, we ca generate sorted Append plans instead of MergeAppend when > >> > sorting occurs on the partition key. > >> > >> Great idea. This is too late for v10 at this point, but please add it > >> to the next CommitFest so we don't forget about it. > > > > I know it is too late, and thought that it was too early to add it to the > > commitfest properly since so many design decisions should be discussed. > > Thanks for the feedback, I added it. > > Thanks for working on this. I was also thinking about the same. > > I will try to get back to review/work with this for v11. Mean time, I > am working on partition-wise joins [1]. In those patches, I have added > a structure called PartitionScheme, which represents how a relation is > partitioned. For base relations it's mostly copy of PartitionDesc and > PartitionKey, but then it bubbles up across join, with each > partitioned join getting relevant partitioning scheme. If you could > base your design such that is uses PartitionScheme, it could be used > for joins and probably when Jeevan's patch for partition-wise > aggregate [2] comes along, it can be used with grouping. > > [1] > https://www.postgresql.org/message-id/CAFjFpRcMWwepj-Do1otxQ-GApGPSZ1FmH7YQ > vQTwzQOGczq_sw%40mail.gmail.com [2] > http://www.mail-archive.com/pgsql-hackers@postgresql.org/msg308861.html
Thank you. I should probably wait until your patch is finalised before spending too much time on it, and I could probably also leverage the incremental sort patch if there is progress on it. -- Ronan Dunklau http://dalibo.com - http://dalibo.org -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers