Re: MERGE/SPLIT PARTITIONS issues/questions

On Fri, Aug 14, 2026 at 10:08 AM Daniel Gustafsson <daniel(at)yesql(dot)se> wrote:
>
> > On 12 Aug 2026, at 22:48, Melanie Plageman <melanieplageman(at)gmail(dot)com> wrote:
>
> > The user needs to add RLS to the new leaf partitions if they want the
> > same level of security, but I'm not sure that's intuitive.
>
> It's not, and it quite easily will leave the data without the intended
> protection during a window.
>
> > Also, for merging partitions, if you merge two partitions that have
> > the same RLS, after merging, the new merged partition doesn't have
> > that RLS policy -- that seems confusing too
>
> I would rank this as even more unintuitive than the previous case, as a user I
> would expect the new partition to have the shared policy.
>
> Could we make this safe by restricting to the cases where partitions match the
> parent and we can make them not drop characteristics? If we want to expand
> which differences can be handled in a safe manner in 20 then we can revisit,
> rather than being very lax now and try to restrict later.

Yes, I don't think it makes sense to silently drop the properties in
19 and then start automatically propagating them in 20. That seems
like it will be really confusing for users that have scripts to, for
example, recreate ACLs for the merged or split partition(s) when using
19.

- Melanie