Re: feature & performance comparison

From: Blair Kenneth Adamache <adamache_at_ca.ibm.com>
Date: Sun, 10 Jun 2001 23:00:22 -0400
Message-ID: <3B243445.E53F5D19@ca.ibm.com>

See appendix M of the SQL Reference, at this page: http://www-4.ibm.com/cgi-bin/db2www/data/db2/udb/winos2unix/support/v7pubs.d2w/en_main

There are three examples, and it talks about controlling depth. Recursive SQL has been in DB2 since 1995.

Mark Townsend wrote:

> in article B749727F.1536B%markbtownsend_at_home.com, Mark Townsend at
> markbtownsend_at_home.com wrote on 6/10/01 6:52 PM:
>
> >> WITH RPL (PART, SUBPART, QUANTITY) AS
> >> ( SELECT ROOT.PART, ROOT.SUBPART, ROOT.QUANTITY
> >> FROM PARTLIST ROOT
> >> WHERE ROOT.PART = '01'
> >> UNION ALL
> >> SELECT CHILD.PART, CHILD.SUBPART, CHILD.QUANTITY
> >> FROM RPL PARENT, PARTLIST CHILD
> >> WHERE PARENT.SUBPART = CHILD.PART
> >> )
> >> SELECT DISTINCT PART, SUBPART, QUANTITY
> >> FROM RPL
> >> ORDER BY PART, SUBPART, QUANTITY
>
> Hmm - actually, there is more to this than I first saw - presumably this
> iterates down through all levels of child ? How is this transformed ? Can
> you push predicates into the traversal ? This may be way cool.
Received on Sun Jun 10 2001 - 22:00:22 CDT