IT358 Unit 7 Synonyms Index and Sequence
Outcomes addressed in this activity:
Describe how the schema objects work
Describe how sequences and indexes are created, modified, and removed within Oracle
Describe when to use an Index
In this project, you will create a view, synonym, and index:
1. Answer the Review Questions #1–5 from Chapter 6.
2. Complete Hands-on Assignments #1-10.
Oracle 11G SQL Chapter 6 Hands-On assignment Solution
1. Create a sequence to use for populating the Customer# column of the CUSTOMERS table. When setting the start and the increment values, keep in mind that data already exists in this table. The options should be set to not cycle the values, not cache any values, and no minimum or maximum values should be declared.
2. Add a new customer row using the sequence created in Question 1. The only data currently available for the customer is as follows: last name = Shoulders, first name = Frank, and zip = 23567.
3. Create a sequence that will generate integers starting with the value 5. Each value should be three less than the previous value generated.The lowest possible value should be 0, and the sequence should not be allowed to cycle. Name the sequence MY_FIRST_SEQ.
4. Issue a SELECT statement that will display NEXTVAL for MY_FIRST_SEQ three times. Because the value is not being placed in a table, use the DUAL table in the FROM clause of the SELECT statement. What causes the error on the last SELECT?
5. Change the setting of MY_FIRST_SEQ so the minimum value that can be generated is –1000.
6. Create a private synonym that will allow you to reference the MY_FIRST_SEQ object as NUMGEN.
7. Use a SELECT statement to view the CURRVAL of NUMGEN. Delete the NUMGEN synonym and MY_FIRST_SEQ.
8. Create a Bitmap index on the CUSTOMERS table to speed up queries that search for customers based on their state of residence. Verify that the index exists, and then delete the index.
9. Create a B-tree index on the customer’s Last Name column. Verify that the index exists by querying the data dictionary. Remove the index from the database.
10. Many queries search by the number of days to ship (number of days between the order and shipping dates). Create an appropriate index that might improve the performance of these queries.