rtfm

G100m 14.02.2006 21:30

The following queries cannot be executed with this quick select method, for the reasons given:

There are other aggregate functions than MIN() or MAX(), for example:

SELECT c1, SUM(c2) FROM t1 GROUP BY c1;

The fields in the GROUP BY clause do not refer to the beginning of the index, as shown here:

SELECT c1,c2 FROM t1 GROUP BY c2, c3;

The query refers to a part of a key that comes after the GROUP BY part, and for which there is no equality with a constant, an example being:

SELECT c1,c3 FROM t1 GROUP BY c1, c2;