On Mon, Apr 25, 2016 at 8:05 PM, Stephen Frost <[email protected]> wrote:
> * Melvin Davidson ([email protected]) wrote: > > Then could you please clarify exactly what structural mods are permitted > by > > *"* > > *Allows modification of the structure of system tables" ?* > > I would say, in short, those modifications which are implemented by PG > developers who know what's safe to do with the catalog tables. > > Beyond that, I'm afriad you'd need to read the source code. I don't > know offhand the complete set of "what's safe to do", though it's > probably a pretty short list and certainly doesn't include adding > columns. > > Ultimately, that switch isn't for end users to use to modify the > catalogs. If you'd like to modify the structure of pg_class, you would > start by looking at src/include/catalog/pg_class.h, though there's quite > a few other bits that would need to change too. > > Thanks! > > Stephen > >allow_system_table_mods only exists so that initdb can do some setup steps that would otherwise be inconvenient to manage. So in essence "*Allows modification of the structure of system tables" does NOT allow _structural_ changes (probably only dml changes) and the documentation should be changed to clarify. -- *Melvin Davidson* I reserve the right to fantasize. Whether or not you wish to share my fantasy is entirely up to you.
