On Mon, Sep 20, 2021 at 3:17 PM Ajin Cherian <itsa...@gmail.com> wrote: > > On Wed, Sep 8, 2021 at 7:59 PM Ajin Cherian <itsa...@gmail.com> wrote: > > > > On Wed, Sep 1, 2021 at 9:23 PM Euler Taveira <eu...@eulerto.com> wrote: > > > > > > Somehow this approach of either new_tuple or old_tuple doesn't seem to > > be very fruitful if the user requires that his replica is up-to-date > > based on the filter condition. For that, I think you will need to > > convert UPDATES to either INSERTS or DELETES if only new_tuple or > > old_tuple matches the filter condition but not both matches the filter > > condition. > > > > UPDATE > > old-row (match) new-row (no match) -> DELETE > > old-row (no match) new row (match) -> INSERT > > old-row (match) new row (match) -> UPDATE > > old-row (no match) new-row (no match) -> (drop change) > > > > Adding a patch that strives to do the logic that I described above. > For updates, the row filter is applied on both old_tuple > and new_tuple. This patch assumes that the row filter only uses > columns that are part of the REPLICA IDENTITY. (the current patch-set > only > restricts this for row-filters that are delete only) > The old_tuple only has columns that are part of the old_tuple and have > been changed, which is a problem while applying the row-filter. Since > unchanged REPLICA IDENTITY columns > are not present in the old_tuple, this patch creates a temporary > old_tuple by getting such column values from the new_tuple and then > applies the filter on this hand-created temp old_tuple. The way the > old_tuple is created can be better optimised in future versions. >
Yeah, this is the kind of idea which can work. One thing you might want to check is the overhead of the additional deform/form cycle. You might want to use Peter's tests above. I think you need to only form old/new tuples when you have changed something in it but on a quick look, it seems you are always re-forming both the tuples. -- With Regards, Amit Kapila.
