Re: Using Indices

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От ADBAAMD
Тема Re: Using Indices
Дата
Msg-id 3AC75A43.2060903@bell.ca
обсуждение исходный текст
Ответ на Using Indices  (Alexander Lohse <al@humantouch.de>)
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Alexander Lohse wrote:

>
> when I use phpPgAdmin to create DBs, my Indices are getting automatic
> names like : pers_UID_key
>
> I am getting confused about the name!
>
> Does that mean a need to do call this in a select query?
>
> "select * from pers where pers_UID_key = '...'"
>
> or do i call the original field?
>
> "select * from pers where UID= '...'"

    In relational databases you should not care much about indices when
writing simple queries.  They are used automagically by the query
planner according to need.  Many times the planner will do a better job
of improving performance than a common programmer.  And if you decide to
change your indices, there's no need to rewrite your programs and queries.

    I would recommend that anyone coming to relational databases read "An
Introduction to Database Systems", 7th Ed, by Chris J Date -
Addison-Wesley, October 1.999, ISBN 0201385902; around US$ 58 used, US$
72 new.  The relational world is very, very different from "navigational
databases", and even if it is far simpler for the user it takes some
getting used to by programmers.



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