On Thu, Sep 24, 2020 at 2:47 PM Amit Langote <amitlangot...@gmail.com> wrote: > On Thu, Sep 24, 2020 at 4:25 AM Etsuro Fujita <etsuro.fuj...@gmail.com> wrote: > BTW, the discussion so far on the other thread is oblivious to the > issue being discussed here, where we need to find a way to transfer > system attributes between a pair of partitions that are possibly > incompatible with each other in terms of what set of system attributes > they support.
Yeah, we should discuss the two issues together. > Although, if we prevent accessing system attributes > when performing the operation on partitioned tables, like what you > seem to propose below, then we wouldn't really have that problem. Yeah, I think so. > > Yeah, but for the other issue, I started thinking that we should just > > forbid referencing xmin/xmax/cmin/cmax in 12, 13, and HEAD... > > When the command is being performed on a partitioned table you mean? Yes. One concern about that is triggers: IIUC, triggers on a partition as-is can or can not reference xmin/xmax/cmin/cmax depending on whether a dedicated tuple slot for the partition is used or not. We should do something about this if we go in that direction? > That is, it'd be okay to reference them when the command is being > performed directly on a leaf partition, although it's another thing > whether the leaf partitions themselves have sensible values to provide > for them. I think so too. Best regards, Etsuro Fujita
