My first response would be "try it & see" - and as others have pointed out, using SELECT rather than SSELECT would have an impact .... BUT, then I got to thinking .... sort order isn't important?
So, my question is "what comes next?" What are you feeding the select into, that doesn't need information in any particular order? Do you even need a BY-EXP if the data can be processed by a program directly from the multi-values ... so, what consumes the list (and why?) Ross Ferris Stamina Software Visage > Better by Design! >-----Original Message----- >From: [EMAIL PROTECTED] [mailto:owner-u2- >[EMAIL PROTECTED] On Behalf Of Boydell, Stuart >Sent: Thursday, 9 August 2007 5:27 PM >To: [email protected] >Subject: [U2] [UV] Speeding up a big BY.EXP select > >I have a large file with an MV set I need to do an exploding sort >against (about 2 million records, about 20 MVs per record). I'm not >actually after any particular sort order but it's taking hours. >I'm wondering if there is any efficiency advantage by telling it to use >a primary sort on the ID or just to sort on the MV attribute? >My (probably flawed) reasoning is that if the primary sort is on the id >then the sort process wouldn't have to build up one big explode - as it >would have a primary sort by record, it then only needs to explode each >record at a time. > >Eg. >SSELECT BIGFILE BY @ID BY.EXP MV.ATTRIBUTE >Or >SSELECT BIGFILE BY.EXP MV.ATTRIBUTE > >Anyone know the answer to that one? > >Stuart Boydell > > > >********************************************************************** >This email message and any files transmitted with it are confidential >and intended solely for the use of addressed recipient(s). If you have >received this communication in error, please reply to this e-mail to >notify the sender of its incorrect delivery and then delete it and your >reply. It is your responsibility to check this email and any >attachments for viruses and defects before opening or sending them on. >Spotless collects information about you to provide and market our >services. For information about use, disclosure and access, see our >privacy policy at http://www.spotless.com.au >Please consider our environment before printing this email. >********************************************************************** >------- >u2-users mailing list >[email protected] >To unsubscribe please visit http://listserver.u2ug.org/ ------- u2-users mailing list [email protected] To unsubscribe please visit http://listserver.u2ug.org/
