On 8/18/21 12:39 PM, Alvaro Herrera wrote: > On 2021-Aug-18, Tom Lane wrote: > >> I wonder though if we could fix the immediate problem with something >> less ambitious. The hard part of the full proposal, I think, is >> separating permanent identity from physical position. If we were to >> split out *only* the display order from that, the patch footprint >> ought to be far far smaller --- basically, I think, we'd need to fix >> star-expansion and not a lot more in the backend. Of course, >> client-side code like psql's \d and pg_dump would need to be upgraded >> too, but any missed things there would be cosmetic that's-not-the- >> expected-column-order bugs, not core dumps. Also, at least in the v1 >> patch we could use this just for system catalogs without exposing it >> as a feature for user tables, which would greatly restrict the set of >> client-side places that really need fixed. >> >> (I think Alvaro was the last person to mess with this issue, so I >> wonder what his take is on the feasibility of such a restricted >> solution.) > Yeah, my impression is that the project of just changing star expansion > is much, much easier than splitting out attribute identity from physical > location. The former, as I recall, is a localized change in expandRTE > and friends, and you don't have to touch anything else. The other part > of the change is much more invasive and got me into territory that I > wasn't able to navigate successfully. > > (I think we should consider keeping 'attnum' as the display-order > attribute, and have the physical-and-identity attribute get a new name, > say attphysnum. That's so that you don't have to change psql and the > whole world -- the change is transparent to them. This means we need a > first step that's very invasive, because every single current use of > 'attnum' has to be changed to attphysnum first, followed by a functional > patch that changes a few of those back to attnum. It'd be a large > inconvenience to backend developers to ease the lives of client-side > developers.)
Can we call it attid just in case we decide some day to break the nexus on the other side? I like the idea of keeping it to the catalog to start with. cheers andrew -- Andrew Dunstan EDB: https://www.enterprisedb.com
