On Wed, Jul 19, 2023 at 2:31 PM PG Doc comments form <nore...@postgresql.org> wrote:
> The following documentation comment has been logged on the website: > > Page: https://www.postgresql.org/docs/15/ddl-system-columns.html > Description: > > Hi, > Looking at the explanation abour ctid, it is "The physical location of the > row version within its table. " > From that line, I think ctid is unique in the table. > Unique but not stable - if you give your actual record an ID value the associated ctid for it may very well change over time and a given ctid can be associated with any number of IDs > And I also think ctid might be unique across the database since it is the > physical location. > The concept doesn't even apply - the value itself only makes sense within a given physical table. i.e., the table is implied. It's like saying "I live at 123 Main St." to someone. Sure in any given place there can only be a single 123 Main St. but that really isn't useful by itself. And to extend back to the previous point, you may live there now but you will likely have a different address in the future and someone else will have 123 Main St. David J.
