On 3/15/17 12:25 PM, Robert Haas wrote: > On Tue, Mar 14, 2017 at 10:08 AM, David Steele <da...@pgmasters.net> wrote: >> This patch is marked as POC and after a read-through I agree that's >> exactly what it is. > > Just out of curiosity, were you looking at Nagata-san's patch, or Amul's?
Both - what I was looking for was some kind of reconciliation between the two patches and I didn't find that. It seemed from the thread that Yugo intended to pull Amul's changes/idea into his patch. >> As such, I'm not sure it belongs in the last >> commitfest. Furthermore, there has not been any activity or a new patch >> in a while and we are halfway through the CF. >> >> Please post an explanation for the delay and a schedule for the new >> patch. If no patch or explanation is posted by 2017-03-17 AoE I will >> mark this submission "Returned with Feedback". > > Regrettably, I do think it's too late to squeeze hash partitioning > into v10, but I plan to try to get something committed for v11. It would certainly be a nice feature to have. > I was > heavily involved in the design of Amul's patch, and I think that > design solves several problems that would be an issue for us if we did > as Nagata-san is proposing. For example, he proposed this: > > CREATE TABLE h1 PARTITION OF h; > CREATE TABLE h2 PARTITION OF h; > CREATE TABLE h3 PARTITION OF h; > > That looks OK if you are thinking of typing this in interactively, but > if you're doing a pg_dump, maybe with --binary-upgrade, you don't want > the meaning of a series of nearly-identical SQL commands to depend on > the dump ordering. You want it to be explicit in the SQL command > which partition is which, and Amul's patch solves that problem. OK, it wasn't clear to me that this was the case because of the stated user-unfriendliness. > Also, > Nagata-san's proposal doesn't provide any way to increase the number > of partitions later, and Amul's approach gives you some options there. > I'm not sure those options are as good as we'd like them to be, and if > not then we may need to revise the approach, but I'm pretty sure > having no strategy at all for changing the partition count is not good > enough. Agreed. Perhaps both types of syntax should be supported, one that is friendly to users and one that is precise for dump tools and those who care get in the weeds. -- -David da...@pgmasters.net -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
