Thread: Re: pgsql: Foreign keys on partitioned tables
On Wed, Apr 4, 2018 at 1:03 PM, Alvaro Herrera <alvherre@alvh.no-ip.org> wrote: > Foreign keys on partitioned tables > > Author: Álvaro Herrera > Discussion: https://postgr.es/m/20171231194359.cvojcour423ulha4@alvherre.pgsql > Reviewed-by: Peter Eisentraut The commit message here was so brief that I had to read the documentation to figure out exactly what this feature was. In so doing, I ran across this, which seems to need some cleanup: + Also, while it's possible to define <literal>PRIMARY KEY</literal> + constraints on partitioned tables, it is not supported to create foreign + keys cannot that reference them. This restriction will be lifted in a + future release. Generally, I think we're better off not committing to doing things in a future release because we never really know what will happen in the future, but the biggest problem here is that "it is not supported to create foreign keys cannot that reference them" doesn't make any sense. I think you mean something like "creating foreign keys that reference a partitioned table is not supported". -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company
Robert Haas wrote: > On Wed, Apr 4, 2018 at 1:03 PM, Alvaro Herrera <alvherre@alvh.no-ip.org> wrote: > > Foreign keys on partitioned tables > > > > Author: Álvaro Herrera > > Discussion: https://postgr.es/m/20171231194359.cvojcour423ulha4@alvherre.pgsql > > Reviewed-by: Peter Eisentraut > > The commit message here was so brief that I had to read the > documentation to figure out exactly what this feature was. I wrote three draft commit messages, and they all seemed to be saying something so obvious (just repeating the commit title) that I decided not to repeat myself. Evidently that was a mistake. > In so doing, I ran across this, which seems to need some cleanup: > > + Also, while it's possible to define <literal>PRIMARY KEY</literal> > + constraints on partitioned tables, it is not supported to create foreign > + keys cannot that reference them. This restriction will be lifted in a > + future release. > > Generally, I think we're better off not committing to doing things in > a future release because we never really know what will happen in the > future, True. I removed that sentence, leaving a "yet" that hints to the future without making (I hope) too much of a promise. > but the biggest problem here is that "it is not supported to > create foreign keys cannot that reference them" doesn't make any > sense. I think you mean something like "creating foreign keys that > reference a partitioned table is not supported". Yeah, I edited this a few times and evidently one word from some previous iteration ("cannot") escaped deletion. I liked your wording so I used it. -- Álvaro Herrera https://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
On Fri, Apr 6, 2018 at 4:49 PM, Alvaro Herrera <alvherre@alvh.no-ip.org> wrote: > Robert Haas wrote: >> On Wed, Apr 4, 2018 at 1:03 PM, Alvaro Herrera <alvherre@alvh.no-ip.org> wrote: >> > Foreign keys on partitioned tables >> > >> > Author: Álvaro Herrera >> > Discussion: https://postgr.es/m/20171231194359.cvojcour423ulha4@alvherre.pgsql >> > Reviewed-by: Peter Eisentraut >> >> The commit message here was so brief that I had to read the >> documentation to figure out exactly what this feature was. > > I wrote three draft commit messages, and they all seemed to be saying > something so obvious (just repeating the commit title) that I decided > not to repeat myself. Evidently that was a mistake. Mainly I couldn't tell which direction(s) had been permitted without looking within. Not a huge deal, just mentioning it. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company