Re: HI
- From: Wolfgang Breitling <breitliw@xxxxxxxxxxxxx>
- To: SrinivasT@xxxxxxxxxxxxxxx
- Date: Mon, 20 Sep 2004 12:02:41 -0600
I was trying to bite my tongue, but now it bleeds so I have to let go:
In my opinion this is an irrelevant, if not invalid, question in a
relational database. Relational databases are built on the theory of sets
of relations and the valid operations ( projection(select),
restriction(where) and join) upon them and as such do not have a concept of
ordering. All operations can be reordered any which way following the
operational rules.
Questions like this, and trying to find THE answer, is what gets you into
trouble. Just think of what the result of the query should look like, not
how to achieve it. You can use any mental model to help you visualize - how
to achieve - the result, as long as you remember that it is only a mental
model and the actual path to achieve the result is up to the database engine.
It's akin to aksing "What is the colour of the number 42?" (Mladen will
probably say it's mauve).
At 11:28 PM 9/19/2004, Srinivas T wrote:
>Hi Friends,
>I am having a very fundamental doubt,
>what is the order of retrival of the clauses when all are inclueded in the
>select stament like.
>
>Where
>Group by
>having
>order by.
>
>eg : select deptno,max(sal) from emp where job like 'SAL%' group by deptno
>having max(sal)>1000 order by deptno
>
>Regards,
>Srinivas
>
>
>--
>//www.freelists.org/webpage/oracle-l
Regards
Wolfgang Breitling
Centrex Consulting Corporation
www.centrexcc.com
--
//www.freelists.org/webpage/oracle-l
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