Skip scanning works on indexes where the leading column has low cardinality.
----- Original Message -----
> Oracle 9.2.0.2.0=20
>
> I have an intersection table composed of PK_TABLE_A, PK_TABLE_B which is
> being used to handle a M:M relationship between A and B. There is a
> unique constraint on the combination of the two entries and a
> corresponding index with A as the leading value. When I was trying to
> access table A using the PK from table B I expected it to use that index
> because of the 9i skip scan feature that allows for a non leading index
> member to still utilize the index. What I got was a FTS until I added a
> separate index on PK_TABLE_B only. Is there something with a unique
> index that prevents skip scanning? Or do I have too much blood in my
> caffeine and am mis-rembering how the indices should work?
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Received on Thu Apr 15 2004 - 08:39:58 CDT
