Later in the day you attempt to create the employees

This preview shows page 66 - 68 out of 152 pages.

You then closed the encryption wallet because you were advised that this is secure. Later in the day, you attempt to create the EMPLOYEES table in the SECURESPACE tablespace with the SALT option on the EMPLOYEE column. Which is true about the result? A. It creates the table successfully but does not encrypt any inserted data in the EMPNAME column because the wallet must be opened to encrypt columns with SALT. B. It generates an error when creating the table because the wallet is closed. C. It creates the table successfully, and encrypts any inserted data in the EMPNAME column because the wallet needs to be open only for tablespace creation. D. It generates error when creating the table, because the salt option cannot be used with encrypted tablespaces. Correct Answer: B Section: (none) Explanation Explanation/Reference: QUESTION 118 On your Oracle Database, you issue the following commands to create indexes: SQL > CREATE INDEX oe.ord_customer_ix1 ON oe.orders (customer_id, sales_rep_id) INVISIBLE; SQL> CREATE BITMAP INDEX oe.ord_customer_ix2 ON oe.orders (customer_id, sales_rep_id);
Image of page 66
Which two statements are true? (Choose two.) A. Only the ORD_CUSTOMER_IX1 index created. B. Both the indexes are updated when a row is inserted, updated, or deleted in the ORDERS table. C. Both the indexes are created: however, only ORD_CUSTOMERS_IX1 is used by the optimizer for queries on the ORDERS table. D. The ORD_CUSTOMER_IX1 index is not used by the optimizer even when the OPTIMIZER_USE_INVISIBLE_INDEXES parameters is set to true. E. Both the indexes are created and used by the optimizer for queries on the ORDERS table. F. Both the indexes are created: however, only ORD_CUSTOMERS_IX2 is used by the optimizer for queries on the ORDERS table. Correct Answer: BF Section: (none) Explanation Explanation/Reference: Explanation: Not A: Both indexes are created fine. B: The invisible index ORD_CUSTOMERS_IX1 and the bitmap index are both updated by DML operations on the Orders table. F: Since ORD_CUSTOMERS_IX1 is invisible only ORD_CUSTOMERS_IX2 is used by the query optimizer. Not C,Not D,Not E: * ord_customer_ix1 is an invisible index and is therefore not used by the optimizer. * VISIBLE | INVISIBLE Use this clause to specify whether the index is visible or invisible to the optimizer. An invisible index is maintained by DML operations, but it is not be used by the optimizer during queries unless you explicitly set the parameter OPTIMIZER_USE_INVISIBLE_INDEXES to TRUE at the session or system level. Note: Specify BITMAP to indicate that index is to be created with a bitmap for each distinct key, rather than indexing each row separately. Bitmap indexes store the rowids associated with a key value as a bitmap. Each bit in the bitmap corresponds to a possible rowid. If the bit is set, then it means that the row with the corresponding rowid contains the key value. The internal representation of bitmaps is best suited for applications with low levels of concurrent transactions, such as data warehousing.
Image of page 67
Image of page 68

You've reached the end of your free preview.

Want to read all 152 pages?

  • Fall '19
  • Oracle Database

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern

Stuck? We have tutors online 24/7 who can help you get unstuck.
A+ icon
Ask Expert Tutors You can ask You can ask You can ask (will expire )
Answers in as fast as 15 minutes
A+ icon
Ask Expert Tutors