Re: Q: is INDEX synonymous with KEY in SQL92?

From	Harry Tuttle <SOZRBLNTLEEE@spammotel.com>
Newsgroups	comp.databases
Subject	Re: Q: is INDEX synonymous with KEY in SQL92?
Date	2013-10-03 15:51 +0200
Message-ID	<bb5b2sFa5pjU1@mid.individual.net> (permalink)
References	<df5d7bcf-bc7d-493c-ba32-74e5621daed2@googlegroups.com> <l2jcl8$q38$1@dont-email.me> <bb4tqdF7aulU1@mid.individual.net> <l2jli5$955$1@dont-email.me>

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Norbert_Paul wrote on 03.10.2013 13:48:
> No. I am just referring to what I learned at university on database
> implementation. See for example p. 60 in
> http://wwwiti.cs.uni-magdeburg.de/iti_db/lehre/db2_en/db2-md-english.pdf

I assume you are referring to slide 2-30 and 2-31

Those statements seem to be strongly influenced by the way SQL Server (or MySQL) implement a primary key.

> Note that the majority (MySQL, SQL Server) of your examples
> (MySQL, SQL Server, "not all DBMS") also works that way. Hence your exaples
> support "usually" whereas "all" would have been wrong.

My "example" was not an "example" it was what I assumed you had in mind.

e.g. Oracle, Postgres, DB2, Firebird, Informix, Vertica, Ingres and Cubrid do not distinguish between a "primary index" and a "secondary" index
i.e. they don't automatically create a clustered index on the primary key - not all of them actually have such a thing as a clustered index.

Teradata does have the notion of a "primary index" but AFAIK that is not a clustered index, it's just the one created to back the primary key definition.

Oracle and DB2 do have a concept of a "clustered index", but they don't automatically create one when you define a primary key constraint

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Q: is INDEX synonymous with KEY in SQL92? jmichae3@yahoo.com - 2013-09-27 16:54 -0700
  Re: Q: is INDEX synonymous with KEY in SQL92? Lennart Jonsson <erik.lennart.jonsson@gmail.com> - 2013-09-30 14:55 +0200
  Re: Q: is INDEX synonymous with KEY in SQL92? Harry Tuttle <SOZRBLNTLEEE@spammotel.com> - 2013-09-30 16:03 +0200
  Re: Q: is INDEX synonymous with KEY in SQL92? Norbert_Paul <norbertpauls_spambin@yahoo.com> - 2013-10-03 11:16 +0200
    Re: Q: is INDEX synonymous with KEY in SQL92? Harry Tuttle <SOZRBLNTLEEE@spammotel.com> - 2013-10-03 12:05 +0200
      Re: Q: is INDEX synonymous with KEY in SQL92? Norbert_Paul <norbertpauls_spambin@yahoo.com> - 2013-10-03 13:48 +0200
        Re: Q: is INDEX synonymous with KEY in SQL92? Harry Tuttle <SOZRBLNTLEEE@spammotel.com> - 2013-10-03 15:51 +0200

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