1Z0-027 · Question #31
You plan to migrate an existing production database supporting online transaction processing (OLTP) workloads to the Exadata Database Machine. The database currently supports an application…
The correct answer is C. Drop non-constraint indexes if Smart Scan performs better than index range scans on the corresponding table. A is wrong. fast full index scan is smart scan and no need to drop non-constraint indexes B is wrong. index unique scan is a unique constraint index, you can not drop that index C is right. index range scan is a non-unique index and can be dropped to allow full table scan which…
Question
You plan to migrate an existing production database supporting online transaction processing (OLTP) workloads to the Exadata Database Machine. The database currently supports an application requiring fast response times, which satisfies stringent requirements, and most of the application queries use index access to the tables in the application schema. For which case would you consider dropping indexes to allow Smart Scans to occur?
Options
- ADrop non-constraint indexes if Smart Scan occurs instead of an index access path on the corresponding table.
- BDrop non-constraint indexes if Smart Scan performs better than index unique scans on the corresponding table.
- CDrop non-constraint indexes if Smart Scan performs better than index range scans on the corresponding table.
- DDrop non-constraint Indexes if Smart Scan performs better than any index scans on the corresponding table.
How the community answered
(31 responses)- A6% (2)
- B16% (5)
- C74% (23)
- D3% (1)
Explanation
A is wrong. fast full index scan is smart scan and no need to drop non-constraint indexes B is wrong. index unique scan is a unique constraint index, you can not drop that index C is right. index range scan is a non-unique index and can be dropped to allow full table scan which is smart scan D is wrong. any index scans include fast full index scan, which is smart scan. so you should not drop that index.
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