Path: dp-news.maxwell.syr.edu!spool.maxwell.syr.edu!news-spur1.maxwell.syr.edu!news.maxwell.syr.edu!postnews.google.com!j33g2000cwa.googlegroups.com!not-for-mail From: "dawn" Newsgroups: comp.databases.theory Subject: Re: MV Keys Date: 3 Mar 2006 14:22:11 -0800 Organization: http://groups.google.com Lines: 31 Message-ID: <1141424531.155515.189200@j33g2000cwa.googlegroups.com> References: <1141239957.788010.239620@j33g2000cwa.googlegroups.com> <1141260473.796686.131530@u72g2000cwu.googlegroups.com> <1141324828.479189.199000@i40g2000cwc.googlegroups.com> <1141393792.003417.56260@e56g2000cwe.googlegroups.com> <1141409876.758527.66510@i39g2000cwa.googlegroups.com> NNTP-Posting-Host: 207.199.203.250 Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" X-Trace: posting.google.com 1141424536 10513 127.0.0.1 (3 Mar 2006 22:22:16 GMT) X-Complaints-To: groups-abuse@google.com NNTP-Posting-Date: Fri, 3 Mar 2006 22:22:16 +0000 (UTC) In-Reply-To: User-Agent: G2/0.2 X-HTTP-UserAgent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.0.1) Gecko/20060111 Firefox/1.5.0.1,gzip(gfe),gzip(gfe) Complaints-To: groups-abuse@google.com Injection-Info: j33g2000cwa.googlegroups.com; posting-host=207.199.203.250; posting-account=fLxfag0AAADzmFPc_IBdM-stGY4WCEYa Xref: dp-news.maxwell.syr.edu comp.databases.theory:37223 Gene Wirchenko wrote: > On 3 Mar 2006 10:17:56 -0800, "Marshall Spight" > wrote: > > >Jon Heggland wrote: > >> > >> Anyway, a counterargument is that introducing lists implies more > >> complexity, less simplicity, and no change in power---the users gets the > >> additional burden of having to learn all the list operators, when they > >> don't really have to. > > > >That's a decent argument, but I think in the final analysis it > >doesn't hold up. Lists are really quite simple, so they don't > >add much cognitive load. Indeed, those from outside the > >RM world are already used to using lists for pretty much > >everything already, whether appropriate or not. The > >cost of having to learn all the list operators is prepaid, > >and was pocket change to begin with. > > So those from outside the RM world are not using lists correctly, > yet you say lists are simple and that people have already learned > them? If you have a list construct available and not a bag, lists will be used as bags. Similarly, if you have list attributes and no set attributes, lists will be used as sets too. I think that is what he meant. It isn't that people don't know how to use a list, but that so many attributes can be modeled with lists, that people are inclined to use them for anything that works. --dawn