Re: Pluggable Storage - Andres's take

Hi,

FWIW, now that oids are removed, and the tuple table slot abstraction
got in, I'm working on rebasing the pluggable storage patchset ontop of
that.

On 2018-11-27 12:48:36 +1100, Haribabu Kommi wrote:
> On Thu, Nov 22, 2018 at 1:12 PM Asim R P <apraveen(at)pivotal(dot)io> wrote:
>
> > Ashwin (copied) and I got a chance to go through the latest code from
> > Andres' github repository. We would like to share some
> > comments/quesitons:
> >
>
> Thanks for the review.
>
>
> > The TupleTableSlot argument is well suited for row-oriented storage.
> > For a column-oriented storage engine, a projection list indicating the
> > columns to be scanned may be necessary. Is it possible to share this
> > information with current interface?
> >
>
> Currently all the interfaces are designed for row-oriented storage, as you
> said we need a new API for projection list. The current patch set itself
> is big and it needs to stabilized and then in the next set of the patches,
> those new API's will be added that will be useful for columnar storage.

Precisely.

> > TupleDelete_function() accepts changingPart as a parameter to indicate
> > if this deletion is part of a movement from one partition to another.
> > Partitioning is a higher level abstraction as compared to storage.
> > Ideally, storage layer should have no knowledge of partitioning. The
> > tuple delete API should not accept any parameter related to
> > partitioning.
> >
>
> Thanks for your point, will look into it in how to change extract it.

I don't think that's actually a problem. The changingPart parameter is
just a marker that the deletion is part of moving a tuple across
partitions. For heap and everythign compatible that's used to include
information to the tuple that concurrent modifications to the tuple
should error out when reaching such a tuple via EPQ.

> Andres, as the tupletableslot changes are committed, do you want me to
> share the rebased pluggable storage patch? you already working on it?

Working on it.

Greetings,

Andres Freund