On Tue, Dec 7, 2021 at 6:31 PM Ashutosh Bapat <ashutosh.bapat....@gmail.com> wrote: > > On Tue, Dec 7, 2021 at 12:18 PM tanghy.f...@fujitsu.com > <tanghy.f...@fujitsu.com> wrote: > > > > I have another problem with your patch. The document says: > > > > ... If the subscription has several publications in > > + which the same table has been published with different filters, those > > + expressions get OR'ed together so that rows satisfying any of the > > expressions > > + will be replicated. Notice this means if one of the publications has no > > filter > > + at all then all other filters become redundant. > > > > Then, what if one of the publications is specified as 'FOR ALL TABLES' or > > 'FOR > > ALL TABLES IN SCHEMA'. > > > > For example: > > create table tbl (a int primary key);" > > create publication p1 for table tbl where (a > 10); > > create publication p2 for all tables; > > create subscription sub connection 'dbname=postgres port=5432' publication > > p1, p2; > > Thanks for the example. I was wondering about this case myself. >
I think we should handle this case. > > > > I think for "FOR ALL TABLE" publication(p2 in my case), table tbl should be > > treated as no filter, and table tbl should have no filter in subscription > > sub. Thoughts? > > > > But for now, the filter(a > 10) works both when copying initial data and > > later changes. > > > > To fix it, I think we can check if the table is published in a 'FOR ALL > > TABLES' > > publication or published as part of schema in function > > pgoutput_row_filter_init > > (which was introduced in v44-0003 patch), also we need to make some changes > > in > > tablesync.c. > > In order to check "FOR ALL_TABLES", we might need to fetch publication > metadata. > Do we really need to perform a separate fetch for this? In get_rel_sync_entry(), we already have this information, can't we someway stash that in the corresponding RelationSyncEntry so that same can be used later for row filtering. > Instead of that can we add a "TRUE" filter on all the tables > which are part of FOR ALL TABLES publication? > How? We won't have an entry for such tables in pg_publication_rel where we store row_filter information. -- With Regards, Amit Kapila.
