On Mon, Oct 26, 2026 at 9:52 AM Amit Kapila <[email protected]> wrote: > > On Mon, Oct 26, 2026 at 9:08 AM shveta malik <[email protected]> wrote: > > > > On Sat, Oct 24, 2026 at 11:42 AM Amit Kapila <[email protected]> > > wrote: > > > > > > The current use of the "datestyle" and other GUCs in libpqwalreceiver > > > or in other places is to keep the format portable across nodes but > > > here the CLT output will be usually human-readable. So, the same > > > analogy doesn't follow here. I am not convinced that this required > > > mid-way changing the GUCs temporarily. I feel we can document this > > > column and if we still get a request from field for portability of > > > this field(s) then we can consider using GUCs to make the format > > > consistent. > > > > > > > But it causes ambiguous results as shown in [1]. I am not sure how > > documentation will help here. As I see it, the stored key must > > convert back to the original value, not to some other value, > > especially since the patch’s own docs recommend casting it back to the > > column type before comparing. And I don’t think libpqwalreceiver does > > this for portability: its comment says it forces these GUCs so values > > are output “in a form that is unambiguous to the subscriber.” IMO, > > that’s the same goal here: avoiding a wrong stored value, not > > portability. > > > > That is a cross-node compatibility case and similarly pg_dump's output > could be restored on another node. I feel if a user changes the > datestyle or similar settings in-between different conflict-insertions > the results can change accordingly. We shouldn't take such guarantees. > It should be documented somewhere along with the following text [1], > we can probably give a small example as well. > > [1] > + <para> > + The apply worker's <xref linkend="guc-bytea-output"/> and > + <xref linkend="guc-quote-all-identifiers"/> settings change how a value > + is written without changing the value itself. If these settings differ > + between conflicts, the same key can be recorded in different but > + equivalent forms, and comparing the recorded text may miss some of them.
Okay. Let's do this, we can decide further if we have any real customer's feedback. thanks Shveta
