> On Jan 27, 2021, at 19:41, Bharath Rupireddy > <bharath.rupireddyforpostg...@gmail.com> wrote: > > On Wed, Jan 27, 2021 at 4:42 PM Amit Kapila <amit.kapil...@gmail.com> wrote: >>> On Wed, Jan 27, 2021 at 3:16 PM Bharath Rupireddy >>> <bharath.rupireddyforpostg...@gmail.com> wrote: >>>> On Wed, Jan 27, 2021 at 3:01 PM Amit Kapila <amit.kapil...@gmail.com> >>>> wrote: >>> So, I think the new syntax, ALTER SUBSCRIPTION .. ADD/DROP PUBLICATION >>> will refresh the new and existing publications. >> That sounds a bit unusual to me because when the user has specifically >> asked to just ADD Publication, we might refresh some existing >> Publication along with it? > > Hmm. That's correct. I also feel we should not touch the existing > publications, only the ones that are added/dropped should be > refreshed. Because there will be an overhead of a SQL with more > publications(in fetch_table_list) when AlterSubscription_refresh() is > called with all the existing publications. We could just pass in the > newly added/dropped publications to AlterSubscription_refresh(). > > I don't see any problem if ALTER SUBSCRIPTION ... ADD PUBLICATION with > refresh true refreshes only the newly added publications, because what > we do in AlterSubscription_refresh() is that we fetch the tables > associated with the publications from the publisher, compare them with > the previously fetched tables from that publication and add the new > tables or remove the table that don't exist in that publication > anymore. > > For ALTER SUBSCRIPTION ... DROP PUBLICATION, also we can do the same > thing i.e. refreshes only the dropped publications. > > Thoughts?
Agreed. We just only need to refresh the added/dropped publications. Furthermore, for publications that will be dropped, we do not need the “copy_data” option, right? -- Regrads, Japin Li. ChengDu WenWu Information Technology Co.,Ltd.
