Re: Status report on writeable CTEs

Marko Tiikkaja <marko.tiikkaja@cs.helsinki.fi>

From: Marko Tiikkaja <marko.tiikkaja@cs.helsinki.fi>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Date: 2010-07-12T18:41:32Z
Lists: pgsql-hackers
On 7/12/10 9:34 PM +0300, Tom Lane wrote:
> Marko Tiikkaja<marko.tiikkaja@cs.helsinki.fi>  writes:
>> ... So what I'm now thinking of is making the planner plan that as a single
>> Query, and make the planner expand it into multiple PlannedStmts if
>> necessary.  This would break the existing planner hooks, but I don't
>> think that's a huge problem.  Does anyone see any obvious flaws in this?
>
> How will that interact with the existing rewriter?  It sounds a lot
> like a recipe for duplicating functionality ...

I was thinking that the rewriter would look at the top-level CTEs and 
rewrite all non-SELECT queries into a list of Queries and store that 
list into the CommonTableExprs.  The planner would then use this 
information and also expand the rewrite products.


Regards,
Marko Tiikkaja