Forcing the Optimizer to Use an Index

You can force the optimizer to use an index by using several techniques. You can use an INDEX hint (there are several of these, as explained later) to tell the optimizer to use a specific index or even any index the optimizer finds best. You can also adjust the initialization parameter optimizer_index_cost_adj, which, by making a direct adjustment to the computed cost of the index access, makes it very likely to cause the database to use an index instead of doing a full table scan.

images Note The effect of adjusting optimizer_index_cost_adj parameter is not really to force an index use per se. Rather, it forces ...

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