On Wed, Dec 10, 2014 at 7:52 PM, Alvaro Herrera <alvhe...@2ndquadrant.com> wrote: > > Amit Langote wrote: > > > On Wed, Dec 10, 2014 at 12:46 PM, Amit Kapila <amit.kapil...@gmail.com> wrote: > > > On Tue, Dec 9, 2014 at 7:21 PM, Alvaro Herrera < alvhe...@2ndquadrant.com> > > > wrote: > > > >> FWIW in my original proposal I was rejecting some things that after > > >> further consideration turn out to be possible to allow; for instance > > >> directly referencing individual partitions in COPY. We could allow > > >> something like > > >> > > >> COPY lineitems PARTITION FOR VALUE '2000-01-01' TO STDOUT > > >> or maybe > > >> COPY PARTITION FOR VALUE '2000-01-01' ON TABLE lineitems TO STDOUT > > >> > > > or > > > COPY [TABLE] lineitems PARTITION FOR VALUE '2000-01-01' TO STDOUT > > > COPY [TABLE] lineitems PARTITION <part_1,part_2,> TO STDOUT > > > > > > I think we should try to support operations on partitions via main > > > table whereever it is required. > > Um, I think the only difference is that you added the noise word TABLE > which we currently don't allow in COPY,
Yeah, we could eliminate TABLE keyword from this syntax, the reason I have kept was for easier understanding of syntax, currently we don't have concept of PARTITION in COPY syntax, but now if we want to introduce such a concept, then it might be better to have TABLE keyword for the purpose of syntax clarity. > and that you added the > possibility of using named partitions, about which see below. > > > We can also allow to explicitly name a partition > > > > COPY [TABLE ] lineitems PARTITION lineitems_2001 TO STDOUT; > > The problem with naming partitions is that the user has to pick names > for every partition, which is tedious and doesn't provide any > significant benefit. The input I had from users of other partitioning > systems was that they very much preferred not to name the partitions at > all, It seems to me both Oracle and DB2 supports named partitions, so even though there are user's which don't prefer named partitions, I suspect equal or more number of users will be there who will prefer for the sake of migration and because they are already used to such a syntax. With Regards, Amit Kapila. EnterpriseDB: http://www.enterprisedb.com