Monday, May 19, 2008

Re: [PATCHES] [HACKERS] WITH RECURSIVE patch V0.1

"Martijn van Oosterhout" <kleptog@svana.org> writes:

> From an implementation point of view, the only difference between
> breadth-first and depth-first is that your tuplestore needs to be LIFO
> instead of FIFO.

I think it's not so simple. How do you reconcile that concept with the join
plans like merge join or hash join which expect you to be able to be able to
process the records in a specific order?

It sounds like you might have to keep around a stack of started executor nodes
or something but hopefully we can avoid anything like that because, well, ick.

--
Gregory Stark
EnterpriseDB

http://www.enterprisedb.com

Ask me about EnterpriseDB's PostGIS support!

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