Thanks for the input - and the article. Seems right. Artificial / surrogate traditionally incremental integers moving over to hash based UUID's
On 20 September 2013 14:52, Geoff Canyon <gcan...@gmail.com> wrote: > On Thu, Sep 19, 2013 at 5:46 AM, David Bovill <david.bov...@gmail.com > >wrote: > > > > > 1. No good reason - historical > > 2. ID lookups tend to be faster > > 3. Some scenarios allow you to derive meaning from incremental > increases > > in the number - ie it is the next in a series > > > > Naturally in Livecode the difference between numbers and strings is > > deliberately and unusually blurred. Still in general it always seemed to > me > > that reasons 2 & 3 were insufficient. Can someone explain why on earth > the > > Twitter API does not just use screen names ( a unique lower case string > of > > 15 chars without spaces) - what is the advantage of also having a 16 > > integer number? > > > > I'm not a DBA, but I'll take a swing at this. > > 1. Databases have auto-increment for numeric keys. It would require work to > do the same thing with strings. > 2. Numeric keys are efficient -- both compact and fast. Maybe not as > important these days, but still a consideration. > 3. Context does matter, so the fact that I can look at a row with a key of > 12345 and know that rows created around the same time will have similar > numbers is useful, even if the table also has columns for the creation > date. > > Finally -- I'm a purist, but primary keys should never be based on actual > data. In other words, they should be artificial -- some say surrogate. > Here's > an essay on keys <http://www.agiledata.org/essays/keys.html>. I only > skimmed it, but it looks reasonable. > _______________________________________________ > use-livecode mailing list > use-livecode@lists.runrev.com > Please visit this url to subscribe, unsubscribe and manage your > subscription preferences: > http://lists.runrev.com/mailman/listinfo/use-livecode > _______________________________________________ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode
