Re: Status report on writeable CTEs - Mailing list pgsql-hackers

From Marko Tiikkaja
Subject Re: Status report on writeable CTEs
Date
Msg-id 4C408028.8080503@cs.helsinki.fi
Whole thread Raw
In response to Re: Status report on writeable CTEs  (Hitoshi Harada <umi.tanuki@gmail.com>)
Responses Re: Status report on writeable CTEs
List pgsql-hackers
On 7/16/10 6:15 PM +0300, Hitoshi Harada wrote:
> Sorry it's not relevant to the topic you post but ..

Relevant enough :-)

> .. it seems you're
> going to add new executor node called DtScanNode and let it hold
> tuplestore passed by the Query indicated by index number. However, I
> suppose there are other ways:
>
> 1. Use MaterialNode instead of adding DtScanNode. Since MaterialNode
> is exsiting one that work with single tuplestore, it might be sane to
> modify this so that it accepts tuplestore from Query instead of its
> child node.

I thought about this, but I don't necessarily like the idea of 
overloading executor nodes.

> 2. Use temp table instead of tuplestore list. Since we agreed we need
> to execute each plan one by one starting and shutting down executor,
> it now looks very simple strategy.

I didn't look at this because I thought using a "tuplestore receiver" in 
the portal logic was simple enough.  Any thoughts on how this would work?

> I'm not familiar with the long discussion on this feature so not sure
> they are possible, but ISTM  they are enough to be discussed (or
> discussed already?).

We haven't discussed this part of the design yet..  Now is a good time 
to do it.


Regards,
Marko Tiikkaja


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