This beta feature is available with release 7.4.4 only. Gert
> -----Original Message----- > From: Gerald Nowitzky [mailto:[EMAIL PROTECTED] > Sent: Dienstag, 24. Juni 2003 11:17 > To: Becker, Holger > Cc: [EMAIL PROTECTED] > Subject: Re: Is performance really this bad?! Experiences, PLEASE! > > > Hi! > I wanted to try the new join algorithm you mentioned and > tried "diagnose new > join on" with the new 7.4.3 Build 25 on W2K, but I just get > an error. Is > there something wrong with the statement or is it only > available from CVS > Builds? > Thanks! > (Gerald) > > ----- Original Message ----- > From: Becker, Holger > To: '[EMAIL PROTECTED]' ; Knappke, Christian > Cc: [EMAIL PROTECTED] > Sent: Wednesday, June 18, 2003 9:59 AM > Subject: RE: Is performance really this bad?! Experiences, PLEASE! > > > [EMAIL PROTECTED] wrote: > > > > The ORDER BY is senseless with unique Forms.Title and > > Kiosks.Name. But it > > tells the database to perform it anyway, thus the "RESULT IS > > COPIED" and a > > lot of temp space usage and sort activity is necessary. > > > > I didn't realise that a join will automatically order it too! > > I guess that > > makes sense. Unfortunately, I need the ordering done by > > Upper case - for > > next version I will add UpperTitle and UpperName columns that are > > automatically updated, but I'm stuck without them at the moment. > > I guess as this is a select query, there is no way to get rid of the > > "result is copied" ie keep it all in memory? > > One remark to the "result is copied" and the join in SAP DB. > > Until now the join algorithm always results in a physically > build result table. So the explain of the join will also shows > "result is copied" without the order by clause. > > Additionally every single join step creates an intermediate > result set which exists until the next join step. > With version 7.4.4 SAP DB will introduce a additionally new > join implementation without those temporary intermediate result. > We hope that this will reduce i/o and temp page consumption > of the join. > The new algorithm is still in beta and test phase and have > to be manually activated with the command "diagnose new join on". > > Kind regards, > Holger > SAP Labs Berlin > _______________________________________________ > sapdb.general mailing list > [EMAIL PROTECTED] > http://listserv.sap.com/mailman/listinfo/sapdb.general > > _______________________________________________ > sapdb.general mailing list > [EMAIL PROTECTED] > http://listserv.sap.com/mailman/listinfo/sapdb.general > _______________________________________________ sapdb.general mailing list [EMAIL PROTECTED] http://listserv.sap.com/mailman/listinfo/sapdb.general
