Group By Questions..
From: Jimmy <c6635500_at_comp.polyu.edu.hk>
Date: Sat, 02 Oct 1999 03:14:49 -0700
Message-ID: <37F5DB19.5363BFB9_at_comp.polyu.edu.hk>
[Quoted] Hello all,
Date: Sat, 02 Oct 1999 03:14:49 -0700
Message-ID: <37F5DB19.5363BFB9_at_comp.polyu.edu.hk>
[Quoted] Hello all,
[Quoted] Assume I have a table with column A, B, C and D.
I wonder the following SQL statements will produce the same results:
i) select B, C, D, avg(A) from AAA group by B, C, D; ii) select B, C, D, avg(A) from AAA group by B, D, C; iii) select B, C, D, avg(A) from AAA group by C, B, D; ....
i.e. does the order of group by clause affect the final result (or performance, if any) of the SQL statement? Anyone knows white papers or documents discussing this issue?
Thanks,
Jimmy
Received on Sat Oct 02 1999 - 12:14:49 CEST