Posted by gilles27 on 10/26/05 12:52

I'm sure Gert-Jan is correct in what he states, however because the
most likely filtering on OrderLines is by Ledger and OrderNumber, those
two should come before OrderLineNumber in the primary key.

I could ask the customer to demonstrate their findings but my pride
prevents me from admitting to them that I don't know what they mean by
"reduced index reads by a factor of 5". :-)

I need some of way checking that my changes to primary keys are
actually having a positive effect, if I could compare the number of
index reads before and after modifying the table, that would help.


Ross

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