Re: Does it make sense to have 2 unique keys in one table?

Sometimes yes, sometimes no. Usually you can make a query take advantage of the index even if you don't really want to use the leading fields. e.g. you would like a query based on columns 3 and 4. To allow the use of the 4 column index you could add cols 1 and 2 into the query even though you don't really need them. Select * from xyz where column1 > 0 and column2 > '' and column3 = 'abc' and column4 > 10; You would need to try this and then use explain plan to see if the optimizer is indeed making use of the index. HTH Jim Gregory >>==========Empty, 10/3/95========== >> >>if the columns are partially duplicated, like >> >>unique key1 unique key2 >>column1 column3 >>column2 column4 >>column3 >>column4 >> >>does this make sense? >> >>-- Bill >> Views and opinions expressed are mine and do not reflect my empoyer's or client's.