Thanks a lot for your reply. I really appreciate it.
I will have only one mark field created for the bottommost NewJoin. The other nodes will just use the same mark field. I just want to make sure that flag propagate up the pipeline.
Thanks again,
ehab
> To: ehabgalal123@hotmail.com
> CC: pgsql-sql@postgresql.org
> Subject: Re: marking tuples
> From: stark@enterprisedb.com
> Date: Wed, 5 Dec 2007 08:44:15 +0000
>
> "Ehab Galal" <ehabgalal123@hotmail.com> writes:
>
> > In my algorithm, each NewJoin node may "mark" its ps_ResultTupleSlot with
> > either red/green. I need that mark to flow in the pipeline so that i can
> > collect them at the top aggregate.
>
> How will you tell about the marks from different NewJoins?
>
> I think you'll have to "project" the tuple and add a resjunk column to
> indicate that flag. I don't know how you'll identify that column from other
> such flag columns other NewJoin nodes have added.
>
> You could look at the setop code in prepunion.c like intersection to see other
> plans which add flag columns. In those cases though they are used by the
> direct parent of the node which added it, so the planner can just mark a field
> in the parent indicating which column it should look at for the flag.
>
> --
> Gregory Stark
> EnterpriseDB http://www.enterprisedb.com
> Ask me about EnterpriseDB's On-Demand Production Tuning
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