Posted by --CELKO-- on 12/05/15 11:29

>> columns with the most distinct values should come first. <<

This is true.

But you also have to remember that an index (a,b,c) in effect gives
you indexng for (a,b) and (a). You might also consider a covering
index to speed up queries. A covering index has all the columns needed
to answer a query so that you do not have to read the base table at
all. Also be sure that the FK and PK lists are in the same order.

[Back to original message]