Re: Avoid orphaned objects dependencies, take 3

Hi,

On Thu, May 23, 2024 at 02:10:54PM -0400, Robert Haas wrote:
> On Thu, May 23, 2024 at 12:19 AM Bertrand Drouvot
> <bertranddrouvot(dot)pg(at)gmail(dot)com> wrote:
> > The reason why we are using a dirty snapshot here is for the cases where we are
> > recording a dependency on a referenced object that we are creating at the same
> > time behind the scene (for example, creating a composite type while creating
> > a relation). Without the dirty snapshot, then the object we are creating behind
> > the scene (the composite type) would not be visible and we would wrongly assume
> > that it has been dropped.
>
> The usual reason for using a dirty snapshot is that you want to see
> uncommitted work by other transactions. It sounds like you're saying
> you just need to see uncommitted work by the same transaction.

Right.

> If that's true, I think using HeapTupleSatisfiesSelf would be clearer.

Oh thanks! I did not know about the SNAPSHOT_SELF snapshot type (I should have
check all the snapshot types first though) and that's exactly what is needed here.

Please find attached v8 making use of SnapshotSelf instead of a dirty snapshot.

Regards,

--
Bertrand Drouvot
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com