Re: Do we still need parent column in pg_backend_memory_context?

David Rowley <dgrowleyml(at)gmail(dot)com> writes:
> On Wed, 31 Jul 2024 at 05:19, Melih Mutlu <m(dot)melihmutlu(at)gmail(dot)com> wrote:
>> After the patch [1] that adds a path column to pg_backend_memory_context, the parent context can also be found in the path array. Since there are currently two ways to retrieve information related to the parent of a context, I wonder whether we still want to keep the parent column.

> My vote is to remove it.

While it's certainly somewhat redundant now, removing it would break
any application queries that are using the column. Simply adding
a column in a system view is a much easier sell than replacing or
removing one.

Perhaps you can make an argument that nobody would be depending
on that column, but I fear that's wishful thinking. Or maybe you
can argue that any query using it is already broken --- but I
think that's only true if someone tries to do the specific sort
of recursive traversal that you illustrated.

regards, tom lane