Feature Requests item #2869851, was opened at 2009-09-29 17:19 Message generated for change (Comment added) made by mlkersten You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=482471&aid=2869851&group_id=56967
Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: SQL - general Group: None >Status: Closed Priority: 5 Private: No Submitted By: Stefan de Konink (skinkie) Assigned to: Nobody/Anonymous (nobody) Summary: SQL: Cross product count, algebra Initial Comment: I think it must be possible for a query like: select count(*) from bigdatabase1, bigdatabase2; To rewrite it to: select (select count(*) from bigdatabase1) * (select count(*) from bigdatabase2); ---------------------------------------------------------------------- >Comment By: Martin Kersten (mlkersten) Date: 2009-12-04 11:27 Message: Too specific transformation. Calls for a math reasoner in the optimizer. Won't be implemented in the foreseable future. ---------------------------------------------------------------------- Comment By: Stefan de Konink (skinkie) Date: 2009-12-01 10:01 Message: This one is on the count, and is partly implemented. The example above here works. The other one is that the sum of the cross product equals the sum of one multiplied by the amount of joins to come to the cross product itself. So count(*)^N vs sum(something)*N ---------------------------------------------------------------------- Comment By: Fabian (mr-meltdown) Date: 2009-12-01 09:55 Message: Sounds very similar to #2875295, is there a big difference? ---------------------------------------------------------------------- Comment By: Stefan de Konink (skinkie) Date: 2009-10-09 02:30 Message: Because I am seriously proud... I want to publish the patch first :D select count(*) from kvk, kvk; % . # table_name % L60 # name % wrd # type % 13 # length [ 5830679502400 ] Timer 2.650 msec 1 rows We have to work on some sort of overflow protection too... but that was already in the /real/ bugtracker :) ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=482471&aid=2869851&group_id=56967 ------------------------------------------------------------------------------ Join us December 9, 2009 for the Red Hat Virtual Experience, a free event focused on virtualization and cloud computing. Attend in-depth sessions from your desk. Your couch. Anywhere. http://p.sf.net/sfu/redhat-sfdev2dev _______________________________________________ Monetdb-bugs mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/monetdb-bugs
