Re: Strategy for Primary Key Generation When Populating Table
От | Andy Colson |
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Тема | Re: Strategy for Primary Key Generation When Populating Table |
Дата | |
Msg-id | 4F3446A3.30906@squeakycode.net обсуждение исходный текст |
Ответ на | Re: Strategy for Primary Key Generation When Populating Table (David Salisbury <salisbury@globe.gov>) |
Ответы |
Re: Strategy for Primary Key Generation When Populating Table
Re: Strategy for Primary Key Generation When Populating Table |
Список | pgsql-general |
On 2/9/2012 4:10 PM, David Salisbury wrote: > > > On 2/9/12 10:08 AM, Rich Shepard wrote: >> I have reports containing macroinvertebrate collection data for several >> hundred (or several thousand) of taxa. There is no natural key since >> there >> are multiple rows for each site/date pair. Years ago Joe Celko taught >> me to >> seek natural keys whenever they might exist. They don't here. That's >> why I >> specifically mentioned that in my message. > > > Interesting. I used to think natural keys were okay, but have since decided > that surrogates are the way to go. That second layer of abstraction allows > for much easier data modifications when needed. What would be an example > of a natural key that would be good to use, and why would it be > preferable?? > > I'd think the key value must never change, and even say kingdom values in a > taxa table could possibly change.. might discover something new and do a > little reordering. :) Also natural keys might be strings, which I'm > thinking > would not be as efficient as integers for an index. > > -ds > Yeah, this is a Vim vs Emacs war. (Vim, :-) ) I prefer surrogates like you. Its way to easy to pick something that one day has to change. Within the last year I remember a long thread about this same thing. -Andy
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