troubleshooting Question

Index utilization question when using wild card searches

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howemrFlag for United States of America asked on
Oracle Database
7 Comments3 Solutions400 ViewsLast Modified:
I'm not a database guy in general, and far more comfortable in MS SQL than Oracle...so apologies in advance.

I have a fairly large table (say 2.5 million rows) with individual indexes on several columns -- A, B, and C.

If I initiate a query with conditions on both indexed and non-indexed fields -- with a wildcard on the non-indexed field(s) -- similar to this:

...WHERE A = "value1" and B = "value2" and K = "%partialvalue%" AND L = "%partialvalue%"...

Will the index on column A and/or B be used at all?  I've been told that it will NOT, but this seems illogical to me.  I would guess the optimizer is smart enough to "handle" this by breaking the request into parts (or something) -- but my understanding of optimizers is about nil.

Thanks!
ASKER CERTIFIED SOLUTION
David VanZandt
Senior Database Administrator

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