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.