I should also clarify that we have a lot of customers we support on mvBase, mvEnterprise, D3 and lots of other platforms, and yes, we do have PI Open customers... I recognize that the topic here is U2, but even there, we have customers who use our products running on Universe 5 (don't ask, we just do...) So, I find that I often have to assume a lowest common denominator when building a reusable solution. I may not always be aware of the current state of a particular platform. I'd love to be corrected if my understanding of limitations is out-of-date! Last I knew, if you wanted to sort an MV file by more than one field, regardless of how many indexes you had, you got to pick one of them, and you would settle for brute force for the others. This was true, last I knew, of EVERY MV platform I knew of that had indexes.
-----Original Message----- From: u2-users-boun...@listserver.u2ug.org [mailto:u2-users-boun...@listserver.u2ug.org] On Behalf Of Robert Houben Sent: Sunday, December 26, 2010 4:42 PM To: U2 Users List Subject: Re: [U2] Migration Should have clarified "when you sort *multiple* fields that are indexed". I still haven't heard anyone tell me that either UV or UD now support more than one indexed field. Let me know if this has changed... -----Original Message----- From: u2-users-boun...@listserver.u2ug.org [mailto:u2-users-boun...@listserver.u2ug.org] On Behalf Of Wols Lists Sent: Sunday, December 26, 2010 4:33 PM To: u2-users@listserver.u2ug.org Subject: Re: [U2] Migration On 24/12/10 15:50, Robert Houben wrote: > SQL will beat MV every time when you sort fields that are indexed. Huh? Ime (UniVerse), that's wrong. Indexes are b-trees, which you can walk, and the contents of the index are sorted. afaik you would have been right about PI, but that's long dead. Dunno about UniData, but UV is a lot of sites where MV will equal SQL ... :-) > For direct reads, MV seems to have a slight advantage. Inserts and > updates that affect indexed fields are slower in SQL (inserts are > painfully slow if you fail to size your SQL table well, but try > "inserting" millions of records into a file with a modulo of 1...) Been there, done that. But that's why most places use dynamic files nowadays. :-) Cheers, Wol _______________________________________________ U2-Users mailing list U2-Users@listserver.u2ug.org http://listserver.u2ug.org/mailman/listinfo/u2-users _______________________________________________ U2-Users mailing list U2-Users@listserver.u2ug.org http://listserver.u2ug.org/mailman/listinfo/u2-users _______________________________________________ U2-Users mailing list U2-Users@listserver.u2ug.org http://listserver.u2ug.org/mailman/listinfo/u2-users
