Hi, Aleksey! On Apr 06, Aleksey Midenkov wrote: > > > But, since we need to specify implicit system fields we cannot > > > avoid adding one more session variable. In my current iteration I > > > made @@force_fields_visible which is more straightforward in what > > > it does: > > > > I'm sorry, I don't understand. > > > > First, visibility is pretty much unrelated concept. > > row_start/row_end can be visible or invisible, and they can be > > writable or not writable - those are orthogonal concepts. > > To be able to specify them in INSERT command they must be at least > user-invisible. System-invisible fields are ignored.
Sure, that's what @@system_versioning_insert_history would do. > > And second, the name is wrong, there are no "fields" row_start and > > row_end unless the user creates then explicitly. They are pieces of > > metadata that every row has, something that Oracle, for example, > > calls "pseudocolumns". Something like > > @@system_versioning_row_start_row_end_visible would be more correct, > > but ugly. In fact, I'd say that @@system_versioning_insert_history > > was the best one. > > I think you are complicating things where complication is not needed. > Pseudo- or not they are fields. No, this is internal implementation detail that can change and it should not leak into the UI. Like, sql_select.cc has a function called sub_select(), but we never tell users that what it does is "subselect", not in the documentation, not in error messages, never. Because it doesn't (it performs one step in a nested-loop join). The fact that some internal enum value is named INVISIBLE_SYSTEM is not something that should affect the user visible behavior. > Besides, the variable is not about system versioning. It can make any > system-invisible fields visible. Which is incorrect. ROWNUM (MDEV-24089) is a pseudocolumn, and it cannot be "visible" in the sense of @force_fields_visible. We don't support ROWID, but if we would — it cannot be visible in the sense of @force_fields_visible either. Basically this variable can only apply to row_start/row_end pseudocolumns, despite its generic name. Regards, Sergei VP of MariaDB Server Engineering and secur...@mariadb.org _______________________________________________ Mailing list: https://launchpad.net/~maria-developers Post to : maria-developers@lists.launchpad.net Unsubscribe : https://launchpad.net/~maria-developers More help : https://help.launchpad.net/ListHelp